New Perspectives in Forensic Anthropology

Dennis C. Dirkmaat,* Luis L. Cabo, Stephen D. Ousley, and Steven A. Symes

Department of Applied Forensic Sciences, Mercyhurst College, Erie, PA 16546

KEY WORDS forensic anthropology; forensic taphonomy; forensic archaeology; trauma analysis

ABSTRACT A critical review of the conceptual andpractical evolution of forensic anthropology during thelast two decades serves to identify two key externalfactors and four tightly inter-related internal methodo-logical advances that have signicantly affected thediscipline. These key developments have not onlyaltered the current practice of forensic anthropology,but also its goals, objectives, scope, and denition. Thedevelopment of DNA analysis techniques served toundermine the classic role of forensic anthropology as aeld almost exclusively focused on victim identication.The introduction of the Daubert criteria in the court-room presentation of scientic testimony accompaniedthe development of new human comparative samplesand tools for data analysis and sharing, resulting in avastly enhanced role for quantitative methods inhuman skeletal analysis. Additionally, new questionsasked of forensic anthropologists, beyond identity,

required sound scientic bases and expanded the scopeof the eld. This environment favored the incipient de-velopment of the interrelated elds of forensic taphon-omy, forensic archaeology, and forensic trauma analy-sis, elds concerned with the reconstruction of eventssurrounding death. Far from representing the mereaddition of new methodological techniques, these disci-plines (especially, forensic taphonomy) provide forensicanthropology with a new conceptual framework, whichis broader, deeper, and more solidly entrenched in thenatural sciences. It is argued that this new frameworkrepresents a true paradigm shift, as it modies notonly the way in which classic forensic anthropologicalquestions are answered, but also the goals and tasks offorensic anthropologists, and their perception of whatcan be considered a legitimate question or problem tobe answered within the eld. Yrbk Phys Anthropol51:3352, 2008. VVC 2008 Wiley-Liss, Inc.

It has been two decades since the publication in thesepages of an inuential article by Mehmet Yasar Iscan(Iscan, 1988) discussing the then current and futurestate of forensic anthropology. In that article, Iscanreviewed the key trends and landmarks in the develop-ment of forensic anthropology during the 1970s and1980s, highlighting the main problems potentiallythreatening the future development of the eld. Muchof the article is devoted to a rather comprehensivereview of developments in the construction of the basicbiological prole from skeletal tissues (age, sex, stat-ure). Very little discussion was devoted to the relevanceof crime scene evidence, and there was no discussionrelative to estimates of postmortem interval and recon-structions of events surrounding the death. Clearly,issues beyond the laboratory-derived observations ofthe bones themselves were not considered to fall underthe purview of what a forensic anthropologist did atthat point in time. Iscan did stress the need forresearch aimed specically at forensic anthropologyapplications, which at the time were hampered by inap-propriate sample materials and strategies, poor analyti-cal standards, and the lack of specic training of foren-sic anthropology practitioners. He indicated that thecommon source of many of the problems within forensicanthropology could be traced to a lack of denition ofthe still nascent eld. As of 1988, the role of the foren-sic anthropologist had yet to be fully understood androutinely accepted by both the anthropological commu-nity and the medicolegal system (Iscan, 1988, p. 222).At this juncture, one might ask how this situation haschanged in the intervening years. This article focuseson the course taken by forensic anthropology sinceIscans (1988) assessment of the state of the eld, itsstrengths, deciencies, needs, and problems ahead.

In a sense, the key question to be posed today iswhether forensic anthropology, as a scientic and profes-sional discipline, is healthier and more robust nowadaysthan it was 20 years ago. At rst glance, it may seem so,at least according to the number of practitioners and theexplosion in the quantity of publications in the eld. The91 members of the Anthropology section of the AmericanAcademy of Forensic Sciences (AAFS) in 1987 increasedto 323 in 2007, many of whom were students. Anotherindicator of the relative health of the eld is that dupli-cating Iscans (1988) comprehensive review of the foren-sic anthropological literature produced during the 20years previous to his article would be quite the monu-mental task today due to the tremendous increase in thenumber of publications and the diversication of topicsdiscussed by the eld in the last two decades. In an opti-mistic interpretation, these developments would seem todocument a healthy, vigorous eld. However, such a rosyportrayal of the eld may not be the only plausible inter-pretation of the raw gures provided above.For example, the high proportion of student afliates

in the AAFS Anthropology section, almost three timeshigher than in any other section (30.65% in Anthropol-ogy, versus 11.31 in the General section in 2007), mayreect instead a difculty for anthropology graduates to

*Correspondence to: Dennis C. Dirkmaat, Department of AppliedForensic Sciences, Mercyhurst College, Erie, PA 16546, USA.E-mail: ddirkmaat@mercyhurst.edu

DOI 10.1002/ajpa.20948Published online in Wiley InterScience

(www.interscience.wiley.com).

VVC 2008 WILEY-LISS, INC.

YEARBOOK OF PHYSICAL ANTHROPOLOGY 51:3352 (2008)

progress eventually into the professional practice of theeld.Perhaps a better way to evaluate the current state of

the eld of forensic anthropology is to ponder a few otherquestions: What role does forensic anthropology playwithin the forensic sciences in general and law enforce-ment in particular (i.e., have forensic anthropologistsacquired any new, unique skills signicantly improvingforensic investigation? If so, are they widely and rou-tinely realized and utilized in forensic investigations?)What is its role relative to physical anthropology (i.e.,does conventional physical anthropology training fullyqualify an individualif you can stomach the smellasa forensic practitioner, or has forensic anthropologyacquired a level of specialization and sophisticationrequiring special training?). Is forensic anthropology afully legitimate scientic discipline, requiring its own ba-sic research, or is it better described as an applied eld,feeding exclusively from methods and research con-ducted within physical anthropology proper?As will be discussed below, these questions cannot be

answered through a mere inventory of the individualcontributions to the literature in the last two decades(on the other hand, as mentioned above, due to thegrowth of the eld this task probably would be impossi-ble today without incurring unfair and unfortunateomissions). To the contrary, far from a simple process ofaccumulating new knowledge and information, thechanges experienced by forensic anthropology in the last20 years represent a shift in the whole contextual frame-work of the discipline. This shift involves not only theway in which we answer some questions or problems,but also which of these can be considered legitimatequestions within the scope of forensic anthropology.We have identied six key developments that have sig-

nicantly altered the trajectory of forensic anthropology.Two of these key developments, representing essentialchanges to the forensic framework itself, arose externalto forensic anthropology: the astounding improvementsin DNA analysis, and the establishment of Daubert crite-ria with regard to admissibility of scientic evidence inthe courtroom.In addition to these two external developments, four

signicant developments occurred within forensic an-thropology in the last 20 years: 1) the pervasive use ofimproved quantitative methods drawn from modern com-parative samples; 2) the re-emphasis on forensic contextthrough the implementation of forensic archaeologicalrecovery methods; and the construction of scienticallybased event reconstructions drawn from 3) forensictaphonomy, and 4) forensic skeletal trauma analysis.Daubert requires forensic anthropologists to substanti-

ate their assertions with scientically tested methodsand, in particular, with probability assessments. Thishas further promoted an improvement and strongerfocus on quantitative methods for hypothesis testing andprobability estimation. Key to this improvement is theidentication and compilation of more appropriate mod-ern comparative samples.Apart from this stronger emphasis in quantitative

methods and models, perhaps the most signicant devel-opment altering the eld of forensic anthropology is theintroduction of forensic taphonomy methods and princi-ples for data collection and analysis. Much as taphonomyaltered human paleoanthropology, forensic taphonomyhas provided a more solid scientic underpinning to thediscipline, from both a methodological and theoretical

point of view, serving as the link to integrate and harmo-nize other subdisciplines within forensic anthropology. Inparticular, the scope and methodological principles devel-oped within forensic taphonomy allowed for the full con-solidation of forensic skeletal trauma analysis, andrequired the inclusion of forensic archaeology, as keynew members of the conceptual framework of forensicanthropology.It will be argued that these changes in the conceptual

framework, paired with the emergent properties arisingfrom the solidication of these new perspectives in theeld, have resulted in a genuine paradigm shift, in theKuhnian (Kuhn, 1970) sense of the term. That is to say,these developments have changed not only forensic an-thropology practice and methodologies, but also thestandards by which the profession determine(s) whatshould count as an admissible problem, or as a legiti-mate problemsolution (Kuhn, 1970, p. 6). One of themain consequences of this paradigm shift is the diversi-cation of the goals and scope of the eld, which in turnhas affected its own essence and denition, providingforensic anthropology with a much stronger and ambi-tious conceptual framework, scientic and methodologi-cal armamentarium, and brighter future.

SIGNIFICANT EXTERNAL INFLUENCES ONFORENSIC ANTHROPOLOGY 1: DNA AND PCR

Perhaps the developments most decisively affectingforensic anthropology since 1988 did not arise within theeld itself, but from molecular biology and the legal sys-tem: the development of polymerase chain reaction(PCR) DNA analytical methods, and the establishmentof Daubert criteria for admissibility of scientic evidencein the courtroom. In the next two sections, we examinethese issues and their impact on forensic anthropology.PCR is a method of DNA amplication based on the

substitution of the enzymatic complex responsible for theinitiation phase of in vivo DNA replication, by in vitrothermal separation (denaturation) of the complementaryDNA strands. The process, devised by Kary Mullin, ismade possible by the utilization in the DNA elongationprocess of a thermostable DNA polymerase (Taq DNAPolymerase), originally obtained from the thermophilicbacterium Thermus aquaticus. The rst application ofthe method was published in 1985 (Saiki et al., 1985),and the rst comprehensive description of the protocolappeared almost as Iscan was completing his review(Saiki et al., 1988). It is difcult to over-emphasize theimportance of the development of PCR for modern foren-sic sciences and the biomedical sciences at large. Still,its relevance for forensic anthropology, at least as it wasdened in the late 1980s, may be even greater. Actually,the development of PCR and subsequent rapid improve-ment of DNA sequencing methods may force a changenot only in forensic anthropological practice, but also inthe denition and goals of the disciplineif it is toremain a viable eld.The classic denition of the eld, as proposed by Stew-

art (1979) and as understood by Iscan (1988), indicatedthat the primary, if almost exclusive goal of forensic an-thropology was aiding in the identication of humanremains in forensic contexts. This goal was attainedthrough the estimation of biological proles (chronologi-cal age, sex, ancestry, stature, and antemortem bonemodication), which served to reduce the list of potentialvictim identities. The amplication of DNA through PCR

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relates to this goal, as it allows for the sequencing ofDNA even from trace samples. What is more importantis that it allows researchers to perform a virtually in-nite number of DNA comparisons, rendering match prob-abilities several orders of magnitude higher than thatcan be attained through biological proles.It may appear initially that DNA analysis does not

necessarily imply a fundamental change from past condi-tions regarding the goals, functions, and perspective offorensic anthropology. After all, providing positive identi-cation (positive ID) from the bones has not commonlybeen one of the primary court-accepted tasks of forensicanthropologists, which instead has fallen to other foren-sic specialists such as forensic pathologists and forensicodontologists. In addition, DNA analysis is still a rela-tively expensive and slow procedure, and the number ofDNA samples routinely submitted for analysis over-whelms forensic laboratories. From this perspective, theclassic goal of biological prole estimation from boneswithin forensic anthropology still remains a unique andsignicant role in simplifying the task of narrowingdown the missing person list.The contribution of forensic anthropologists to the

United States Disaster Mortuary Response Teams(DMORT) may serve as an example to support this opti-mistic view. DMORT was constructed in the mid 1990sto serve as rapidly deployable multidisciplinary humanidentication teams, involving the whole spectrum of for-ensic ID professionals (Sledzik, 1996, 1998; Saul andSaul, 1999) in cases of mass fatalities overwhelminglocal resources. Since its implementation, DMORT teamshave proven effective in a wide variety of mass disasterscenarios, from plane crashes to mass suicides and large-scale oods (see for example, Ubelaker et al., 1995; Sled-zik and Hunt, 1997). Given that most of the biologicalremains at these sites typically consist of commingled,fragmented, and often burned or badly decomposed tis-sues, it is only natural that the contribution of partici-pant forensic anthropologists soon became vital in mostof these scenarios (Sledzik and Rodriguez, 2002). How-ever, the recent emplacement of DNA collection teams,and especially the steep increase in the biological itemssubject to DNA analysis (rapidly nearing 100% in manyscenarios), suggest that the role of all forensic specialistsin these mass disaster teams may change dramaticallywithin the next few years.As a matter of fact, when the current trends in DNA

analysis are closely examined, it soon becomes clear thatthe current state of affairs is inevitably bound to change.In the last two decades, the limiting steps of DNA analy-sis have rapidly shifted from DNA amplication to DNAsequencing, and thence to sample comparison and match-ing, resulting in a rapid decrease in DNA processingtimes and costs. PCR has become an almost routine pro-cedure, available in most biomedical research and prac-tice centers. Visual comparison from electrophoresis inagarose and polyacrylamide gels has been replaced byautomated capillary electrophoresis in the modern DNAsequencers, allowing the processing and sequencing of alarge number of samples simultaneously. More impor-tantly, robust DNA databases for sample comparison havebeen created and made available to the forensic commu-nity, with the reference samples growing at an astoundingrate. As of October 2007, the Combined DNA Index Sys-tem (CODIS) contained 194,785 forensic proles (fromcrime scenes) and 5,070,473 convicted offender proles(http://www.fbi.gov/hq/lab/codis/national.htm).

At present, the only issues preventing routine andwidespread victim identication solely based on DNAcomparisons are the costs and time required for ampli-cation, sequencing and comparison, as well as the needto provide potential matches, currently based on samplescollected ad hoc from the family members of the poten-tial victims. Overcoming these limitations only requiresan improvement in sequencing techniques to an extentmuch smaller than what has transpired during the lasttwo decades, and the inclusion of the DNA sequences offamily members of all missing persons in CODIS orequivalent databases. The question is not whether thiswill happen, but when. When this point is reached, ifpositive ID remains as the main and almost exclusivegoal of forensic anthropology, forensic anthropologists(and odontologists) may become mostly superuous inmost cases, other than those involving commingledremains, where element matching will still result in asignicant decrease of sampling, amplication, andsequencing efforts (see Adams and Byrd, 2008).Therefore, if forensic anthropology is to remain a use-

ful, vibrant scientic discipline, it is necessary to shiftthe scope of the eld from mere identication to a largerrange of problems. As will be discussed below, this shiftof scope has already begun to take place during the lasttwo decades, not necessarily as a direct result of theimprovement in DNA analysis, but as a natural develop-ment derived from an increased focus in taphonomy, for-ensic archaeological techniques, and trauma analysis.

SIGNIFICANT EXTERNAL INFLUENCES ONFORENSIC ANTHROPOLOGY 2:THE IMPACT OF DAUBERT

Iscan (1988) stressed the dual nature of the forensicanthropologist as a scientist and as a professional. Withregard to the scientic end of the discipline, he discussedextensively the necessity of improving research stand-ards and complained about the obsolescence and inad-equacy of the available comparative osteological collec-tions. As will be discussed below, the lack of appropriatesamples has been somewhat remediated in the last deca-des with the collection and curation of modern samplesand data. On the other hand, Iscan could hardly haveimagined the Copernican shift that the legal systemwould experience in the ensuing years regarding thetreatment of scientic evidence presented in court.Recent court cases beginning with the Supreme Court

decision in Daubert vs. Merrell Dow Pharmaceuticals(113 S.Ct. 2786) have dramatically changed approachesto research, evidence, analysis, and expert witness testi-mony in forensic anthropology (Feinberg et al., 1995;Steadman et al., 2006). Daubert stressed that testable,replicable, reliable, and scientically valid methods areto be used to justify scientic opinions. Testing and repli-cation of the methods and conclusions are an essentialpart of reliability. Reliability, the ability to produce con-sistent results, can also be judged by the use of testedscientic methods, described in peer-reviewed publica-tions, and enjoying general scientic acceptance. Valid-ity, or the measure of how well test results produce cor-rect answers, is to be measured when possible bydirectly estimated error rates. Innovative methods canbe employed if they can be independently tested (Fein-berg et al., 1995). Forensic scientists, including forensicanthropologists, have responded to the Daubert decisionby publishing validation studies of previously accepted

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methods, some of which were found wanting (Benjamin,2001; Harrington et al., 2003; Olson, 2003; Christensen,2004; Steadman et al., 2006).The impact of the Daubert decision is most strongly

expressed in changes in the Federal Rules of Evidence(FRE), which are evidence guidelines applicable to fed-eral civil and criminal cases and are also followed bymany states. The Daubert decision was primarily aresponse to situations generated by professional expertwitnesses, whose specialty was testifying in class actionlawsuits, most often involving toxic torts (e.g., detri-mental effects of drugs or treatments that were allegedto cause birth defects or fatalities). In many of thesecases, experts though possessing academic credentials,would deliver opinions based on circumstantial correla-tions and unpublished results. Most importantly, the sci-entic and statistical signicance of possible causal linksbetween drug use and symptoms were left to theseexperts. Furthermore, the recognition of a person as anexpert depended on academic credentials and experiencerather than the reliability and validity of the methodsapplied to the facts of the case.In 2001, after other cases afrmed the changes result-

ing from Daubert (such as Kumho Tire Co. v. Carmi-chael, (119 S.Ct. 1167 [1999]), FRE Rule 702 wasappended to emphasize the connection between the dataand methods used and served to focus on the admissibil-ity of the conclusions, rather on the credentials of theexperts. Replicable methods are essential and specifydirect results, rather than analogies. In that vein, dataanalyses using quantitative methods are preferred overthose employing qualitative methods (Feinberg et al.,1995). The testability and reliability of methods are nec-essary to establish that the conclusions are objectivelyarrived at rather than subjectively determined. Inessence, Rule 702 merely reminds us that scientic con-clusions must be based on accepted scientic principles.It can be said that the Daubert case moved the spot-

light from the experts experience back to the expertsmethods. Because of the focus on methods, Daubert rein-forced the view that forensic anthropologists should bescientists rst and professionals second. One concreteexample of the impact of these judicial rulings is thegreater use of quantitative methods in all aspects of thediscipline of FA today, representing one of the four keyinternal developments that have altered signicantly theeld during the last two decades.

KEY DEVELOPMENTS WITHIN FORENSICANTHROPOLOGY 1: IMPROVEMENTS IN

QUANTITATIVE METHODS

To the extent to which they represent scientic crite-ria, the Daubert standards seem to have increased theurgency of improving analytical methods in forensic an-thropology, previously called for by Iscan (1988) andothers. One of the main arguments posed by Iscan atthat time was that there was an urgent need to improveprobability assessments of biological prole techniques.Critical to these improvements was the need to assemblenew comparative samples that were more representativeof modern populations. Both issues can be considereddifferent aspects of the same problem. The availablesamples were outdated, and hardly represented the mod-ern populations from which forensic inferences weredrawn. Estimates of sex, age, or stature obtained from

those samples were biased when applied to modern pop-ulations due to secular changes in overall body size,health, activity, and nutritional status. Ancestry esti-mates were even more inappropriate, due to the absencein those samples of new signicant ancestry groupswhose numbers increased in the last decades, as well asto the often biased methods used to assign the individu-als to the ancestry groups when the samples werecollected.

Creating new modern comparative samples: TheBass Collection and Forensic Data Bank

These biases also represented a serious limitation forquantitative studies, affecting not only forensic inferencebut also forensic anthropology research. The collectionand curation of new forensic databases during the lasttwo decades has served to alleviate this problem, provid-ing much more accurate estimates and boosting quanti-tative research. The best example of this solution in thelast 20 years has been the establishment of the ForensicAnthropology Center at the University of Tennessee(UT), Knoxville, which includes the AnthropologyResearch Facility (ARF), the William M. Bass SkeletalCollection (BSC), and the Forensic Data Bank (FDB).ARF was originally established to study human decom-position, but ARF has been so successful at requestingvoluntary body donations that it has become the primarycontributor to the BSC, the most up-to-date collection oflate twentieth century human skeletons in the UnitedStates. The Bass collection currently includes the skele-tal remains of over 600 individuals, and will likely over-take the Terry collection (1,600 individuals) within adecade.The BSC is a substantial component of the FDB,

which was started in 1986 with a grant from theNational Institute of Justice (Jantz and Moore-Jansen,1988). The FDB contains extensive demographic infor-mation from the BSC and from forensic cases conductedby UT Department of Anthropology personnel and otheranthropologists from around the country. Extensive in-formation in the FDB includes age, sex, ancestry, stat-ure, weight, place of birth, medical history, occupation,and other demographic information. The skeletal infor-mation in the FDB includes cranial and postcranial met-rics, suture closure information, various aging criteriascores, nonmetric cranial information, perimortemtrauma, congenital traits, and dental observations. Atthis writing, the ARF has 225 bodies in its care andhas a waiting list of 1,400 individuals who havearranged to have their remains donated after death (LeeMeadows-Jantz, personal communication). The FDB cur-rently has information from over 2,600 individuals,1,100 of which are from forensic cases with denite sexand ancestry attribution. Approximately 750 of these1,100 have been positively identied.The BSC and the FDB offer the novelty of being repre-

sentative of the populations confronted by forensicanthropologists at two levels. First, they are drawn fromcontemporary populations, reducing the bias derivedfrom secular changes. Second, the FDB is largely com-posed of and updated from actual forensic cases, in thisway representing not only the contemporary Americanpopulation, but also in a sense, the exact subset of thatpopulation actually studied by forensic anthropologistsin their day-to-day work.

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(Daubert and) quantitative methods in forensicanthropology: Fordisc

Data from the FDB were initially used to test forensicmethods developed from the Terry Collection (Smithso-nian Institute, Washington, D.C.) and Hamann-Todd col-lection (Cleveland Museum of Natural History, Cleve-land, Ohio), including the pioneering Giles and Elliott(1963) discriminant functions (Ayers et al., 1990). Theseskeletal collections (composed largely of unclaimedbodies from the early twentieth century), have beenshown to be inadequate as a basis for analyzing modernforensic cases due to secular changes and other factors.In fact, discriminant function analysis using postcranialelements (Iscan and Cotton, 1990), which were based onthe Hamann-Todd collection, have been shown to beinaccurate when applied to modern groups, especiallyWhite males, due to secular increases in their lowerlimbs (Ousley and Jantz, 1993). As a result, new statisti-cal methods have been developed based on more-recentdata from the FDB, which also includes more middle-class individuals (Jantz and Moore-Jansen, 1988; Ousleyand Jantz, 1992, 1993; Jantz and Ousley, 2000). Fordiscis a computer program that analyzes measurementsfrom unknown skeletal remains and classies them intoknown sex and ancestry samples from the FDB usingmultivariate statistical techniques (Jantz and Ousley,1993, 2005; Ousley and Jantz, 1996). Fordisc is currentlyused by nearly all practicing American forensic anthro-pologists, and is a logical extension of the need to de-velop new forensic statistical techniques in light of mor-phological changes in American groups in the last 150years.Given that Fordisc uses well-established methods of

multivariate analysis that were developed in the 1930s,the focus rightfully belongs to the samples used in com-parisons, and more samples are needed for ner grainedanalyses that may well be of increasing importance inhuman identication, independently of the time periodconsidered. An example of the utility of these ne-grained analyses is related to determining afliation ofprehistoric Native American remains under the NativeAmerican Graves Protection and Repatriation Act(NAGPRA). Along with archaeological context, quantita-tive methods have been extensively used to link individ-ual remains to a specic tribe having been at times theprimary source for assessing tribal identity (Ousley andBilleck, 2001; Hollinger et al., 2005; Ousley et al., 2005).In the last 20 years, forensic anthropology has pro-

vided extensive empirical results to refute the typologi-cal concept in examining variation within groups such asAmerican Whites (Ousley and Jantz, 2002), Africangroups (Spradley, 2006; Spradley et al., 2008), Hispanicgroups (Ross et al., 2004; Slice and Ross, 2004; Spradleyand Jantz, 2005), and East Asian groups (Ousley et al.,2003). Furthermore, this research in quantitative meas-ures has prompted a re-evaluation of nonmetric charac-teristics previously used in the assessment of ancestry(Hefner and Ousley, 2006; Hefner, 2007; Hefner et al.,2007).In the last decade, the use of geometric morphometric

methods in forensic anthropology to analyze landmarkdata has greatly increased, as it has in paleoanthropol-ogy, having been used to investigate and understand var-iation in modern groups (Ross et al., 1999; Slice andRoss, 2004; Ousley and Martinez, 2006). Applications inhuman identication have been limited, but will no

doubt increase as more departments begin using three-dimensional digitizers (Ousley and McKeown, 2001).The buildup of modern skeletal collections and data-

bases, as well as of new analytical methods derived fromthem predated the Daubert decision. However, Daubertreinforced the need for modern samples as a basis fortesting traditional analytical methods as well as develop-ing new methods, and the evolution from experience-based analyses to replicable methods, often involvingstatistical analysis. Statistics is the science of predictionand certainty, and Daubert demands estimates of scien-tic certainty in conclusions.

KEY DEVELOPMENTS WITHIN FORENSICANTHROPOLOGY 2: FORENSIC TAPHONOMY

According to Thomas Kuhn, the key developments in ascientic discipline that represent true turning pointsare those producing a shift in the problems available forscientic scrutiny (Kuhn, 1970, p. 6). In this sense, ifwe are to search for key developments that have takenplace within forensic anthropology during the past twodecades, few issues would t Kuhns description as per-fectly as the evolution of forensic taphonomy.Forensic taphonomy has dramatically changed the

entire playing eld of forensic anthropology. The neces-sity of acquiring contextual data for proper taphonomicinterpretation has been a leading force to transform for-ensic anthropology from an essentially laboratory-basedsubject, into a scientic discipline with a strong eldcomponent. In a sense, taphonomic analysis has allowedforensic anthropologists to mature into full-blown foren-sic professionals, with a denite and irreplaceable rolenot only in the laboratory, analyzing skeletal remains,but also during customary crime scene investigations.Today less than at any point in the past, forensic anthro-pologists cannot be considered forensic sidekicks, whomay be useful advisors when forensic pathologists or lawenforcement step into an unusual case or situation, butthe most appropriate, and most logical rst choice pro-fessionals in cases involving all manner of outdoor crimescenes and commingled or severely altered humanremains. It remains one of the main challenges for theeld to convey this fact to the law enforcement commu-nity and, alas, to many forensic anthropologists. It is ourbelief that promoting a better understanding of the im-portance, objectives, and rationale of forensic taphonomyis a key element to attain this goal.In particular, the dramatic and rapid impact of tapho-

nomic method and theory on forensic anthropologicaltheory and practice can be explained by the striking sim-ilarities in the main goals of both disciplines, whichmake taphonomy an extremely powerful and useful toolfor forensic inference. Comparing and understandingthese shared goals requires at least a brief historicalreview of the development of vertebrate taphonomy,especially during the last three decades.

A brief history of taphonomyand forensic taphonomy

Taphonomy was born as a branch of paleontology. Itwas originally dened as the study of the transition (inall its details) of animal remains from the biosphereto the lithosphere or geological record (Efremov, 1940,p. 86). Taphonomy was therefore initially orientedtoward the study of transport, fossilization, and diagenetic

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processes affecting biological organisms, particularly withrespect to those aspects most inuential in introducingbias in the fossil record. The differential preservationpotential of some structures and organisms, as well astheir transport and deposition in locations away from theirhabitation areas, severely affect community studies, esti-mates of species abundances, and paleoenvironmentalreconstruction. Taphonomy was primarily aimed at detect-ing and controlling these biases.Even though Efremov (1940) repeatedly stressed the

unique relevance of the new discipline for the study ofterrestrial and vertebrate assemblages, it was not untilthe decades from the late 1960s to the 1980s that thediscipline reached full development in vertebrate paleon-tology. This was probably due to the initial focus on dia-genesis and the mineralization process, more relevantfor the preservation of invertebrate structures than ver-tebrate structures.The 1970s witnessed a sharp quantitative and qualita-

tive increase in vertebrate taphonomy research and pub-lications. The new literature focused initially on classicsubjects, such as transport (e.g., Voorhies, 1969; Wolff,1973), bone weathering and preservation processes (Boazand Behrensmeyer, 1976; Behrensmeyer, 1978), and, ingeneral, site formation issues (Voorhies, 1969; Brain,1970; Patterson et al., 1970; Isaac et al., 1971). Signi-cantly, the new momentum of vertebrate taphonomyresearch was largely linked to its successful applicationto hominid sites (e.g., Brain, 1970; Isaac et al., 1971;Boaz and Behrensmeyer, 1976; and the collection ofarticles in Behrensmeyer and Hill, 1980). The new trendwas therefore almost immediately adopted and champ-ioned by physical anthropology, as exemplied by theboom in volumes published on the subject in the early1980s (notably Behrensmeyer and Hill, 1980; Binford,1981; Brain, 1981; Shipman, 1981).The growth and maturation experienced by vertebrate

taphonomy during the 1970s, brought about two keydevelopments, particularly relevant for physical and for-ensic anthropology, during the following decade. First,taphonomy went from a strictly paleontological disciplineto become an essential and universally accepted compo-nent of archaeological practice. Unmistakably tapho-nomic manuals such as Grayson (1984) and Klein andCruz-Uribe (1984) referred to archaeology even in theirtitles. Gifford (1981) considered taphonomy and paleoe-cology as sister disciplines of archaeology. The conse-quences of this association may not look particularly im-pressive or dramatic to modern practitioners, but inessence it meant that assemblage analysis and site anal-ysis could no longer be approached as independent activ-ities, to be performed by different professionals operatingindependently in different observational venues (i.e.,eld and laboratory). Osteological analysis required elddata, specically collected with that analysis in mind. Ata deeper level, apart from gradually (and sometimespainstakingly) dragging osteologists out of their labora-tories, this change brought archaeology (and anthropol-ogy with it) closer to its origins as a geological discipline(for a discussion on the early development of archaeologyin relation to geology, see Adovasio, 2003).The second key development derived from the mar-

riage of anthropology and taphonomy was the introduc-tion of a new approach to taphonomic studies. As men-tioned above, the classic approach to the treatment oftaphonomic information from faunal vertebrate assemb-lages resulted in the reconstruction of site depositional

histories and the paleoecological and environmental con-ditions of the living community. From this viewpoint,which can be termed the paleontological approach (Ring-rose, 1993), the role of taphonomy was to strip the paleo-ecological information from that overprint derived fromsite formation and postmortem alteration processes.When applied to anthropological sites, however, some

taphonomic variables acquire prime importance as thengerprint of past hominid behavior and subsistencepatterns. In other words, whenever humans becometaphonomic agents, the study of the resulting tapho-nomic effects and processes becomes a primary goal, notin order to control for biases derived from taphonomicalteration, but as a vehicle to infer human behavior.Ringrose (1993) refers to this second scope as thezooarchaeological approach in taphonomy.The zooarchaeological approach resulted in an

increased number of studies analyzing cutmarks andbone fractures (e.g., Bromage and Boyde, 1984; Lewin,1984; Villa et al., 1986; White, 1986). Other studies com-bined both approaches, and focused on differentiatinghuman from nonhuman bone alterations (e.g., Shipmanand Rose, 1984; Behrensmeyer et al., 1986; Blumen-schine and Selvaggio, 1988; Olsen and Shipman, 1988;Bonnichsen and Sorg, 1989).Stripping the postmortem inuences from the evidence

is equivalent to assessing forensic signicance in thetrauma methods described below. Assessment of humanversus nonhuman causation in archaeological assemb-lages is identical to the forensic objectives, methods, andmaterials required to assign forensic signicance. Con-versely, forensic trauma analysis is essentially the infer-ence of human behavior based on marks left on bone.The taphonomic approach provides a wealth of experi-ence and information on the biomechanics of degradedbone, as well as on postmortem alteration by differentphysical and biological agents, not available from themedical framework.

Forensic taphonomy and its impact onforensic anthropology

The virtually identical goals of forensic anthropologyand taphonomy explain the relatively rapid and dra-matic impact that taphonomy had on forensic anthropol-ogy. Lyman (1994) can be considered the landmark refer-ence with respect to the generalization and normaliza-tion of vertebrate taphonomy theory and practices,permitting its direct application to archaeological sites.Among other merits, this reference served to standardizethe confusing and sometimes misleading terminology ofthe eld, including the denitions of the main tapho-nomic processes and quantitative indices. Particularlyimportant and permeating throughout the entire book isthe assumption that taphonomy is an essential compo-nent in the analysis not only of paleontological, but alsoof archaeological sites. Still, with respect to forensic an-thropologya eld that has traditionally been particu-larly resistant to fundamental changes, remaining faith-ful to positive ID as its main and almost exclusive goalfor decadesthe rst monograph on forensic taphonomy(Haglund and Sorg, 1997a), including original research,postdated Lyman (1994) by only 3 years.The apparent eagerness of forensic anthropology to

adopt taphonomic principles and techniques is especiallysignicant in view of its drastic consequences not onlyfor the praxis of forensic anthropology, but also for its

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principles, goals, and objectives. Essentially, forensictaphonomyand its right-hand companion forensicarchaeologyexpanded the goals of forensic anthropol-ogy far beyond its original denition and the positive IDparadigm.Iscan (1988) did not include a discussion on forensic

taphonomy or even mention the word taphonomy once.What he described as postmortem assessment was pri-marily a discussion of trauma analysis and issues rele-vant to resolving cause and manner of death, and not ofcircumstances surrounding death. As evidenced by thebulk of the paper, the focus of the eld was squarely inthe arena of providing evidence (primarily, a biologicalprole) that may help to identify the victim. Forensic an-thropology was clearly considered by her practitioners asa laboratory-based discipline.This view, and the analytical questions derived from

it, contrast with the range of questions and analyticalapproaches populating Haglund and Sorgs seminaledited volumes (1997a 2002) in the eld of forensictaphonomy. Rather than simply focusing on the biologi-cal prole, the different contributions in these volumeshighlight issues such as tissue decomposition, scaveng-ing, bone transport, and site formation as key considera-tions in forensic anthropology (Haglund and Sorg, 1997a,2002). Their denition of the eld stands as a guidepostthat anticipates signicant change in perspective in theeld of forensic anthropology. For them, forensic taphon-omy is dened as the use of taphonomic models,approaches, and analysis in forensic contexts to estimatethe time since death, reconstruct the circumstancesbefore and after deposition, and discriminate the prod-ucts of human behavior from those created by the earthsbiological, physical, chemical, and geological subsystems(Haglund and Sorg, 1997b, p. 3).

Addressing issues beyond identity

This new approach does not originate from an out-of-the-blue theory, or as an attempt to expand the forensicanthropology market for egotistical or employment pur-poses. It emanates from current forensic practice and isthe natural consequence of the evolution of the eld, asit embraced novel and more powerful methods to serveits original goals. Taphonomic methods offered signi-cant advances in subjects such as the analysis of com-mingled remains, within the classic goal of aiding in pos-itive ID and assessing forensic signicance. The applica-tion of taphonomic methods and consequent research inforensic anthropology inevitably resulted in newemergent properties that provide completely new datasets, reconstructions, and tasks. This led to an expansionof the range of questions that could be answered by for-ensic anthropology beyond its traditional and largelyself-imposed boundaries of skeletal identication (Snow,1982, p. 97).As will be discussed below, although forensic taphon-

omy is more closely related to the zooarchaeologicalapproach to the analysis of skeletal assemblages, it alsobenets from the classic paleontological approach andtechniques. Both zooarchaeological and paleontologicalstudies require essentially the same contextual data andrecordation techniques (Lyman, 1994). Therefore, whileretrieving eld data necessary for trauma analysis andassessing forensic signicance, the forensic anthropolo-gist will collect information useful for reconstructingdepositional history and site formation (see Hochrein,

1997, 2002). In other words, the application of tapho-nomic techniques to forensic scene processing impliesthe collection of information relevant to reconstructingthe events surrounding death, body disposal, and place-ment at the scene. In this way, forensic taphonomy inevi-tably adds these elements to the primary goals of foren-sic anthropologists, resulting in improved and renedclassic tasks, while adding new tasks, resulting in anewly dened, more relevant role in forensic investiga-tions.Among the new outcomes derived from forensic tapho-

nomic analysis, three are particularly relevant and com-monly sought: 1) scientically grounded estimates ofpostmortem interval (time-since-death), based on decom-positional factors (primarily soft tissue, but in laterstages may include bone modication factors), entomo-logical evidence, chemical methods, and associated physi-cal evidence modication; 2) reconstructions of the origi-nal position and orientation of the body; and 3) charac-terizations of the role played by human intervention (asa taphonomic agent) on the remains, through the processof stripping away (Gifford, 1981) all other naturalagents affecting the remains.These new goals and analyses require new data and

data sources. As mentioned above, most of these newdata come directly from the crime scene, and are notlimited to the human remains. As a matter of fact, thescope and methodological background underlying theanalyses oriented toward these outcomes cannot be prop-erly explained without providing an overview of the datacollection strategies that make them possible. Thisserves to illustrate the key importance of forensicarchaeology, and its intimate relationship with tapho-nomic analysis.

KEY DEVELOPMENTS WITHIN FORENSICANTHROPOLOGY 3: FORENSIC ARCHAEOLOGY

(FORENSIC TAPHONOMY IN PRACTICE)

Forensic archaeology is not exactly a newcomer to theforensic anthropology world. Iscan included a rathershort section on Crime Scene Archaeology, which hedescribed as techniques to search the area and collectthe remains (Iscan, 1988, p. 219). His descriptions ofthe eld and the uses for archaeological recovery, how-ever, were quite limited, suggesting only that theemployment of archaeological methodology could be usedfor analyzing and reconstructing the environmentwhere human remains are found (Iscan, 1988, p. 219).Pioneering articles by Brooks (1975), Bass and Birkby(1978), Skinner and Lazenby (1983), and especiallyMorse et al. (1983), indicated that forensic archaeologywas far more than just collecting remains. Snow (1982,p. 118) even wrote that spatial distribution of bones,teeth, and other items recovered in surface nds canhelp in determining the original location and position ofthe body. However, forensic archaeology to theseauthors was still considered to be a eld or subeld sep-arate from forensic anthropology proper, which was con-ducted by physical anthropologists. Forensic archaeologyinvolved the application of simple archaeological recov-ery techniques in death scene investigations involving aburied body or skeletal remain (Morse et al., 1983,p. 1). These efforts would maximize recovery of evidenceand minimize subsequent damage to the bodies andskeletons.

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Despite the recognition of the utility of forensicarchaeology, up until the mid 1980s recovery of contextat forensic scenes through archaeological practices wasneither common nor particularly rigorous. Law enforce-ment ofcials were charged with processing all outdoorcrime scenes, often merely collecting the remains andshipping them to the appropriate experts. This lack ofboth rigor and success is probably related to a lack ofdenite analytical goals and objectives, as well as the ab-sence of training in recovery and documentation proto-cols. Why go to all that trouble if the only reward is anice map of the scene?The introduction and recognition of forensic taphon-

omy represented a pivotal change, since it provides theconceptual and analytical framework for forensic archae-ology. As discussed above, among the most importantoutputs of forensic taphonomic analysis is determiningwhether humans played a role in emplacing the body inthat location and/or subsequently modifying the remainsat the scene. This information can sometimes be partlydrawn from the laboratory analysis of the humanremains, especially with respect to surface modicationof the bones related to animal gnathic activity, staining,and sun bleaching. However, comprehensive, accuratedeterminations rely heavily on the analysis and identi-cation of all of the natural agents (animals, plants,gravity, soils, etc.) affecting the remains in situ. Can nat-ural agents explain the distribution of the remains? Isthere any evidence of animal activity, or can gravity and/or water ow alone explain the disarticulation and scat-tering of the remains? Is the distribution of the burnedbone fragments in a re pit consistent with an unat-tended re, or were the human remains repositionedduring combustion to promote faster cremation? Is thehead (with no evidence of carnivore activity) foundupslope instead of down-slope? Does the stratigraphicposition of a particular piece of potential evidence placeit at the scene after, during, or before victim placement?Additionally, bone degradation, soft tissue decomposi-

tion, and consequently postmortem interval estimates,depend decisively on natural factors such as tempera-ture, humidity, light exposure, vegetation coverage, soilcomposition, or burial depth, factors that cannot beinferred from the laboratory analysis of the humanremains. All this information is also pertinent and neces-sary for trauma analysis, and requires the recordation ofdata not only from the human remains, but also fromthe scene itself. Proper handling and on-site documenta-tion of the remains also simplies data analysis, byreducing and documenting recovery-related additionalpostmortem trauma.

The evolution of forensic archaeology

Apart from the conceptual and methodological frame-work provided by forensic taphonomy, since the late1980s another four key developments have led to thecurrent conguration of forensic archaeology: 1) meth-odological improvements in contemporary eld archaeol-ogy, 2) implementation of new technology into archaeol-ogy, 3) development of analytical techniques that cantake advantage of spatial data generated by forensicarchaeological recovery, and 4) development of archaeo-logical recovery methods specic to forensic contexts.

Archaeological method and theory. During the lasttwo decades, improvements to archaeological excavationmethodologies have been developed and implemented at

a number of American sites, led by J.M. Adovasio andthe excavation of Meadowcroft Rockshelter in southwest-ern Pennsylvania (Carlisle and Adovasio, 1982; Adova-sio, 2007). The presentation of Meadowcroft as an exam-ple of pre-Clovis occupation of North America was ini-tially met with extreme criticism and cynicism becauseit ew in the face of conventional wisdom. However, Ado-vasios attention to exacting excavation methods of thedeposits of the rockshelter at microstratigraphic levels,and extremely careful attention to context and associa-tion ultimately helped convince the archaeological com-munity of the validity of an early occupation of NorthAmerica, as best emplied by Meadowcroft. This was fol-lowed by state-of-the-art investigations at open sites likeMonte Verde in Chile (Dillehay, 1989, 1997) and theWindover Bog near Titusville, Florida (Doran, 2002); col-lectively, these studies have set the standards in eldarchaeology today.

Technology in archaeology. Associated with and fun-damental to a renewed focus on how to excavate anarchaeological site was the implementation of technologyinto the eld documentation process in two areas: sitemapping and remote sensing. Previously, noting the dis-tribution of artifacts and physical evidence was com-pleted through detailed, hand-drawn plan and prolemaps. Technological innovations applied to outdoor crimescenes have revolutionized the recordation of spatialdata (McPherron and Dibble, 2002). Instruments such asthe electronic total station allow for the very precisenotation of exact relative position and orientation ofeach item on the crime scene. Global positioning system(GPS) instruments permit precise absolute location ofthe scene on the earth. As in paleontological taphonomy,the often tedious effort of documenting the precise loca-tion and orientation of each bone is greatly facilitated bythe routine use of these instruments, especially wheneld work is carried out by the same specialists perform-ing the laboratory analyses, who are, therefore, aware ofthe variables relevant to the analysis, and the way inwhich these must be recorded and coded.Nowadays, total stations are a common tool in most

law enforcement agencies, who use them in varied tasks,but mainly for mapping and reconstructing vehicle acci-dents. In archaeology, they were rst used in the 1980s(McPherron and Dibble, 2002; Adovasio, 2007), and onforensic archaeological sites in the 1990s (Dirkmaat,1998b). In 1994, total stations were used for the rsttime to carefully map the distribution of evidence andhuman remains at the USAir Flight 427 crash site(Dirkmaat and Quinn, 1995; Dirkmaat and Adovasio,1997), proving that their implementation allows fortimely comprehensive recording of all spatial data evenin complex situations, with thousands of evidentiaryitems scattered across a large area. The collection of evi-dence distributional data by the total station is now astandard part of all enhanced forensic crime recoveryprotocols, both small scale (Dirkmaat, 2001; Dirkmaatand Cabo, 2006) and large scale, including plane crashes(Dirkmaat and Hefner, 2001; Reineke and Hochrein,2008). Data collection procedures are further enhancedtoday through the use of in-eld and hand-held com-puters, computerized data recording forms, digital pho-tography, and wireless data transmission protocols.

Analytical techniques for the analysis of the spatialdistribution of evidence. Whereas most forensic inves-tigators are aware of the state-of-the-art improvements

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in data acquisition techniques and instrumentation (e.g.,GIS, GPS, total stations, hand-held scanners, etc.), thesame awareness is certainly not as common regardingrecent developments in analytical techniques. Knowledgeof these analytical improvements plays an importantrole in the design of eld protocols, since these techni-ques, apart from being capable of addressing a widerrange of questions, also require a greater amount ofmore precisely recorded data.During the last few decades, advancements in com-

puter programming and availability have dramaticallyincreased the number of techniques and analytical toolsavailable for statistical analysis. Spatial analysis techni-ques commonly employed in the elds of physics, engi-neering, biochemistry, physiology, and forest ecologyallow the researcher to test theoretical models regardingdifferent aspects of the spatial data collected in the eld.These models can be contrasted with the observed distri-bution either under parametric assumptions or throughempirically obtained distributions, allowing them to suc-cessfully confront an almost endless range of problemswith great exibility.At present, these incipient techniques are restricted to

the analysis of scenes with multiple victims, such asmass graves and mass disasters, and have been mainlyoriented toward the classic problem of victim identica-tion, especially with respect to solving comminglingissues. For example, Tuller et al. (2008) report successrates close to 100% in matching commingled remainsthrough spatial techniques, by applying the nearestneighbor criterion in mass graves with large numbers ofindividuals. Dirkmaat et al. (2005) showed that the basicassumption of spatial association underlying this analy-sis still holds in severely altered features, such as pre-historic ossuaries or secondary mass burials.The current limitation to larger scale scenes is derived

from the large amount of data required by these analyti-cal techniques. Still, they can also be applied in inter-scene comparison, in which each individual forensic casewould be analogous to an experimental replica. Conse-quently, a wider range of application is expected as spa-tial data from individual scenes pile up. In this sense, amore important effort is required, not only to popularizeand rene forensic anthropology, but also to normalizeand enhance data integrity, recording and sharing, inorder to make possible proper data analysis.

Archaeological methodologies specic to forensiccontexts. When the term forensic archaeology is dis-cussed, it is most often in the context of recovery of bur-ied remains alone. Obviously, much of contemporaryarchaeology is devoted to the recovery of buried deposits,understanding and interpreting stratigraphy, and rigor-ously applying Stenos Laws in efforts to understandhow and when artifacts entered the archaeological re-cord. The goals of archaeological investigation also texactly with those of forensic scene investigation. Theevidentiary value of any item at the scene will dependon its relative position and contextual relationships withother evidence and elements at the scene. In the case ofburials, re, or even surface-scattered remains, thesecontextual relationships are essentially stratigraphic innature, and are subject to the same alterations and nat-ural inuences as archaeological materials. It is, there-fore, logical that many archaeological techniques and,especially, basic archaeological principles can be directlyapplied to forensic contexts. Still, some fundamental dif-

ferences do exist between archaeological sites and foren-sic scenes, requiring the modication of conventionalarchaeological techniques, and the development of newmethodologies outside the purview of archaeology.Apart from the time and legal constraints discussed

above, the main difference between conventional archae-ology and forensic archaeology resides in the presence ofsoft tissues at forensic scenes. This requires the develop-ment and implementation of additional sampling proto-cols for the collection of organic evidence. For example,although the forensic anthropologist will not be analyz-ing entomological evidence or DNA, as the primary sceneprocessor it will be necessary to collect this type of evi-dence as carefully and efciently as the geneticist or for-ensic entomologist would.Soft tissue also adds additional time and legal con-

straints to the outdoor crime recovery, as soft tissues areevidence undergoing degradation. To avoid further dete-rioration and loss of evidence, as well as to maintain thechain of custody, forensic anthropologists must processthe site as quickly and as efciently as possible. Anyalteration that the remains may experience from thescene to its deposit at the autopsy facilities must be care-fully documented and appropriate conservation/preserva-tion measures taken.Archaeological principles are also employed in the sys-

tematic and comprehensive search for archaeological evi-dence, in what is termed archaeological surveying (seeBanning et al., 2006 for an updated review of the sub-ject). These same principles can be applied in the docu-mentation of surface-scattered human remains at bothsmall scenes involving one or small numbers of victimsor fatal re scenes, as well as large-scale scenes, such asplane crashes. Searches for unlocated scenes in the pastrelied upon efforts conducted by law enforcement of-cials (Miller, 2003; Swanson et al., 2006; Lee, 2007;Saferstein, 2007). The incorporation of archaeologicalsearch methods (Joukowsky, 1980; Feder, 1997) hasresulted in efcient and effective pedestrian searches forsurface remains in forensic cases (Dirkmaat and Adova-sio, 1997). Because of the presence of soft tissues or freshorganic matter, cadaver dogs have also played a role inlocating evidence when both the trainer and the dog areproperly trained (Rebmann et al., 2000). The combina-tion of cadaver dogs and systematic search techniquesresults in near 100% probability of locating humanremains on the surface within a search corridor.The detection of clandestine graves is a much more

difcult task. In recent years, a wide variety of newtechnologies and search techniques have been utilized tolocate buried features (Killam, 1990). Particularly, suc-cessful efforts have been obtained with multidisciplinaryapproaches that utilize geophysicists, archaeologists, andforensic anthropologists (France et al., 1992, 1997).Remote sensing, such as Ground Penetrating Radar, con-ductivity meters, resistivity meters, and even metaldetectors have certainly aided the search for buried fea-tures (Dupras et al., 2006). Research derived from theUT Decomposition Research Facility has provided usefuldata (Rodriguez and Bass, 1985).Reference to, and training in archaeology and archaeo-

logical methods has led to dramatic improvement in therecovery of evidence associated with burial features(Carlisle and Adovasio, 1982; Dirkmaat et al., 1993;Dirkmaat and Cabo, 2006). Hochrein (2002) has dis-cussed an autopsy of the grave in which geotapho-nomic evidence in the form of geophysical characteris-

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tics associated with the grave feature are carefullynoted. These geophysical characteristics include strati-cation evidence, toolmarks on the burial pit edge, biotur-bation of the deposits, sedimentation factors, surfacecompression and depression of the burial pit deposits,and internal compaction of the burial pit deposits(Hochrein et al., 2000). The key concept in the recoveryof the buried body feature is that all of the materialassociated with the burial, from the back dirt pile to theburial ll and not just the body in the grave, should beconsidered as evidence and handled accordingly.

But wont it take too long?

The foregoing discussion clearly indicates that biologi-cal proling, taphonomic analysis, and forensic archaeol-ogy can therefore be considered as inseparable aspects ofthe same analysis, rather than independent subdisci-plines. When properly implemented and combined, theycan provide extremely relevant forensic information,simplifying and relieving law enforcement of some cru-cial, but unpleasant tasks. If this is the case, the ques-tion is why forensic archaeology in particular is notmore widely utilized. The answer to this question ismainly related to a common misconception, seeminglywidespread among law enforcement and even someanthropologists: forensic archaeological techniques arenot realistically applicable at many case scenes due totime (and personnel) constraints. This assumption isfundamentally wrong: indeed, when properly imple-mented, and with the aid of technology, forensic archaeo-logical techniques are as quick and efcient as any otheron-site forensic technique, and result in a signicantgain in relevant data.

KEY DEVELOPMENTS WITHIN FORENSICANTHROPOLOGY 4: HUMAN SKELETAL

TRAUMA ANALYSIS

The fourth important turning point in the eld of for-ensic anthropology (following Kuhns logic) in the last 20years has been a fundamental change in how we dealwith forensically relevant bone trauma and the resultingenhanced range of trauma questions that can beaddressed by the discipline. Importantly, osteologicaltrauma analysis is now considered as part of the stand-ard professional expertise of forensic anthropologists.Only 20 years ago, interpretation of all forms of

trauma to forensic victims was conducted almost exclu-sively by forensic pathologists in the morgue. Traumaanalysis to bone was neither commonly perceived as partof their tasks, nor routinely practiced by forensic anthro-pologists. For example, Iscan (1988) only discussedtrauma very briey, primarily with respect to what hecalled postmortem assessment. Descriptions focused onchild abuse (what was then described as battered infantsyndrome) and little else. Iscan briey mentioned incipi-ent research in trauma drawn from forensic cases,described in Maples (1986), and work done in medicalexaminers ofces in which anthropologists were just be-ginning to assist forensic pathologists (Smith et al.,1987). Most of the baseline information regarding trau-matized bone at that time was derived from paleopathol-ogy (e.g., Ortner and Putschar, 1981).Paleopathologists have described many different types

and general characteristics of trauma, generally basedon the study of historic materials. References to forensic

pathology and trauma cases involving soft tissue arelargely absent in most of the major bibliographical refer-ences of the eld (e.g., Aufderheide and Rodriguez-Mar-tin, 1998; Bennike, 2008). With respect to trauma analy-sis, paleopathologists suggest that it is difcult and of-ten impossible to make a distinction between fracturesoccurring at the time of death and those that occur sub-sequent to death and burial (Ortner and Putschar,1981, p. 72). Further, distinguishing trauma resultingfrom an accident and that resulting from intentional vio-lence is problematic in archaeologically derived skele-tons. The study of historic materials, with little room forcorroboration of the proposed hypotheses, carried there-fore a large weight of uncertainty and, at best, educatedguessing, inappropriate for forensic contexts (especiallyconsidering the watchful eye of Daubert standards).Additionally, it was perceived that training in clinical

traumatology better equipped forensic pathologists to an-alyze all forms of trauma, from soft tissue damage totraumatized bones. The role of the forensic anthropolo-gist regarding trauma analysis was supposed to be atbest simply describe any evidence of bone damage, pointout its location in relation to vital centers, explain thepossibility of it having been sustained at the time ofdeath or otherwise, and discuss the likely types ofobjects that produce damage (Stewart, 1979, p. 76).Limiting the forensic anthropologists role in traumaanalysis to merely providing descriptive procedureslargely perpetuating the maxim (still almost a mantra inthe profession) that anthropologists are not allowed tocontribute ofcial opinions with regard to cause andmanner of death.This perception of bone trauma analysis as a discipline

extraneous to forensic anthropology, and within theexclusive sphere of forensic pathology and traumatology,would change as a result of three major events in the an-thropological study of skeletal trauma: 1) research in themorgue alongside the forensic pathologist; 2) incorpora-tion of bone biomechanics research drawn from a varietyof disciplines, in conjunction with routine microscopic ex-amination; and 3) the rise of forensic taphonomy.

Research in the medical examiners ofce

In the early 1980s, some progressive minded forensicpathologists and medical examiners hired forensicanthropologists to work as full-time employees in themorgue documenting decomposition, identifying isolatedbones, and serving as death investigators. This situationwas best exemplied in the Memphis, Tennessee, Medi-cal Examiners Ofce under the guidance of Dr. J.T.Francisco and, later, Dr. O.C. Smith. The forensicanthropologists were able to assist autopsy examinationsand even participate in the processing of outdoor scenes.Anthropologists, thus, were part of the multidisciplinaryteam investigating a wide variety of cases, includingthose involving signicant soft tissue in various stages ofdecomposition, sorting animal from human bones, andidentifying fragmented osteological materials (Smithet al., 1990; Symes and Smith, 1998; Galloway et al.,1999). As mentioned above, many of these areas wereconsidered far outside of the purview of forensic anthro-pology, and beyond what forensic anthropologists alleg-edly could, and even should do.It was quickly realized that forensic pathological ex-

amination of trauma cases beneted greatly from a morein depth analysis of the underlying skeletal elements

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(Smith et al., 1987). These forensic anthropological anal-yses typically included maceration of soft tissue, micro-scopic examination of the bones and, eventually, reten-tion of traumatized bone elements as evidence in futuretrials. In essence, multidisciplinary efforts by forensicpathologists and anthropologists served to highlight thelimitations of clinical traumatology, and the advantagesof an anthropological perspective for some key aspects offorensic inference (Smith et al., 1990; Symes and Smith,1998).Clinical trauma analysis focuses on living tissues, and

is primarily oriented toward fracture treatment andreduction rather than to the analysis of the relationshipsbetween trauma defects, inicting agents or forces, andresulting bone modication patterns. Pathologists, there-fore, are ill-equipped to answer certain forensic ques-tions, including those related to fracture timing. Sincedetermining whether a defect under examination wasinicted perimortem (thus, being forensically signicant)or postmortem is an essential question in forensictrauma interpretation. The key element required tomake this distinction is an understanding of the differ-ent responses of fresh, organic bone, and dry, denatur-ized bone, to stress and strain. A combination of biome-chanical research and taphonomic analyses helpedaddress that methodological gap.

Incorporating bone biomechanics research

After death, the biochemical composition of bonechanges with time, especially in terms of the amountand preservation of its organic matrix. From a biome-chanical point of view, the main consequence of thesechanges is a reduction in the elasticity of bone materials(elastic decay) that occurs as bone goes from the fresh(perimortem) to the dry (postmortem/taphonomic) state,in the parlance of classic anthropological literature(Johnson, 1985; Harkess et al., 1991). Fresh bone con-tains normal physiological quantities of organic matrix.When subjected to stress, it will react in a predictablemanner (following Youngs modulus) with a signicantelastic component before fracturing. Therefore, as the or-ganic matrix is degraded after death, the bone progres-sively becomes an increasingly plastic material, produc-ing completely different patterns of fracture and defor-mation. This is particularly relevant for traumaanalysis, as interpretation of skeletal trauma is essen-tially based on what is observable as a result of the bonehaving been plastically deformed.The consideration of the evolving biomechanical char-

acteristics of the degrading bone transfers the analysisfrom clinical traumatology to the realms of vertebratetaphonomy, for which forensic anthropologists are betterprepared. The transcendence and utility of this migra-tion can probably be better understood in light of thechanges that it implies for the concepts of ante-, peri-,and postmortem intervals themselves.As a consequence of elastic decay, there is a temporal

discrepancy between the concepts antemortem, perimor-tem, and postmortem (taphonomic), as used by anthro-pologists and pathologists in medicolegal settings. Ante-mortem can readily be categorized as occurring beforedeath, or more specically identiable as a visible vitalreaction from living tissue. The concepts of perimortemand postmortem, however, are not so easily delineatedbetween the medical and anthropological communities.In the case of sharp force trauma examination, an

anthropologists assessment of a dismemberment case isessentially performed within the theoretical perimortemcontext, as the skeletal material will retain nearly allthe same properties as it showed in life (Symes et al.,2002). However, the dismemberment of a body beforedeath would clearly be an unusual circumstance and,therefore, medical personnel would consider the actpostmortem.As a result, anthropologists must consider skeletal

trauma primarily in a taphonomic context. Defectsoccurring in bone must be excluded as taphonomic in na-ture before they can be considered to have occurred inthe perimortem interval. Although careful taphonomicinterpretations can reveal information concerning cir-cumstances surrounding death and postmortem interval(Dirkmaat and Adovasio, 1997), perimortem traumainterpretation is often essential to coroners and patholo-gists burdened with the death certicate. Therefore,accurate and conservative interpretation of contextualtaphonomic data ultimately reduces confusion by simpli-fying key variables (. . .) regarding cause and manner ofdeath (Symes et al., 2002 p. 430).The biomechanical approach also affects trauma classi-

cation, shifting category criteria from the inicting toolto physical factors such as force and speed. The biome-chanical properties of bone inuence its ability to absorbenergy, as well as its stiffness, density, and fatiguestrength. Bone fractures are also decisively dependenton extrinsic factors including the rate, duration, magni-tude, and direction of force (Evans, 1973; Gozna et al.,1982; Frankel and Nordin, 1989; Harkess et al., 1991;Berryman and Symes, 1998). For example, during animpact at meters per second scale, such as a gunshot,the combination of force and speed will promote localenergy release (fracture) before plastic deformation canoccur. On the other hand, a sharp instrument, such as aheavy knife or an axe, can produce plastic deformationbetter described as blunt force trauma, depending on thedirection of impact, the impacting tool surface, and thearea inicted.In addition, the morphology of the fracture rarely

reects information specic to the inicting tool in bluntforce trauma. Therefore, trauma can be better analyzedand interpreted by focusing on determining the exactdirection, orientation, and patterning of fracture initia-tion and propagation, as they pertain to the directionand speed (energy) associated with the inicting force.This requires detailed and meticulous microscopic exami-nation of minute evidentiary details, with methods ofteninvolving casting of skeletal material, particularly whenanalyzing and interpreting sharp force trauma (Symes etal., 1999). It may also involve the adoption of entirelynew photo-documentary and analytical technologies suchas polynomial textural mapping (Malzbender et al.,2001).

New perspectives on the analysis of humanskeletal trauma

In 1996, a multidisciplinary workshop presented atthe AAFS, best exemplied the impact of this reconsider-ation of skeletal trauma from an anthropological per-spective, as opposed to a paleopathological perspective(Symes et al., 1996). Recent research in newly denedkey areas of forensically relevant trauma, are brieysummarized below.

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Blunt force trauma. Blunt force trauma is perhaps themost difcult area of skeletal trauma to interpret on thebasis of skeletal characteristics alone. Although patholo-gists can use skin alteration and damage characteristicsto accurately estimate the number of blows, forensicanthropologists must estimate numbers of blows by bonefracture patterns that are always difcult to interpret.Recent research, however, indicates that old notions ofhow bone breaks as a result of slow loading impacts(blunt force) are highly inaccurate (e.g., Gurdjian et al.,1950). Characteristics of the bones have been shown toprovide some information with respect to: 1) exactimpact location; 2) angle of impact; and 3) number ofimpacts. However, as noted above, fracture shape anddimensions rarely indicate much about the shape of theimpacting weapon (Symes et al., 1996).

Ballistics trauma. Despite the fact that ballistictrauma is dissimilar to other skeletal trauma and pro-duces characteristic pattern of fractures, confusion com-monly arises in ballistic interpretation due to underesti-mates of velocity, or a lack of understanding of how bul-lets travel at nal velocity (e.g., they do not ricochet atsteep angles off of bone surfaces).Because of the high velocity of the projectile involved,

the damage imparted by ballistic trauma is immense. Abullet initially creates a plug-and-spall, which producesdiagnostic entrance and exit wounds in bone. Withenough energy, subsequent radiating fractures are exten-sive and may indicate the direction of the bullet. If thebullet possesses enough kinetic energy, concentric heav-ing fractures will form. These concentric fractures arecharacterized by an outward bevel, as opposed to theinward bevel found in concentric fractures caused byblunt trauma (Smith et al., 1987; Symes et al., 1996; DiMaio, 1999; Hart, 2005). By recognizing and properlyinterpreting these patterns of modication to bone, theforensic anthropologist can reconstruct the path of thebullet, provide a range of bullet calibers based on the di-ameter of the defect (Berryman et al., 1995; Ross, 1996),determine the number of shots red, and even distin-guish in which order these shots entered the body.

Sharp force trauma. Perhaps the best-researched areaof trauma in the new era of forensic anthropology is thatof sharp force trauma resulting from a wide variety ofimplements, from knives to saws, and ranging fromactivities as disparate as stabbings to dismemberments.Lethal knife wounds are second only to gunshot woundsas a cause of homicidal deaths (see Martin, 1999) and,as such, have received considerable attention in the for-ensic literature (Di Maio and Di Maio, 1993, p. 191;Spitz, 1993, p.252). Unfortunately, knife wound analysishas rarely been effective due to the employment of dubi-ous categories such as sharp or single-edged, as wellas other misleading or errant descriptive terminologylike hesitation marks (Symes et al., 1999, 2002).With respect to saw marks in bone, until recently, the

rarity of this evidence often led to the assumption ofthem being of little use in forensics (see Bonte, 1975;Andahl, 1978; Symes, 1992). Saw marks were seldomgiven more notice than a presence or absence assess-ment by the forensic examiner. In the last two decades,research in saw mark analysis (Symes, 1992; Symeset al., 1998, 2002, 2007; Saville et al., 2007) has revealedthat much can be learned through a careful analysis ofthe marks left on the bone by the saw tool, especiallywhen utilizing low power microscopic examination. This

key information includes: 1) the dimensions and shape ofthe blade and teeth of a saw; 2) how the tool was pow-ered, mechanically or manually; and 3) how a tool wasused (including direction of cut) to accomplish the dis-memberment or mutilation (Symes, 1992; Symes et al.,1998, 2002).Two additional areas of trauma analysis benet

greatly from an anthropological perspective: the recogni-tion of child and elder abuse, and the distinctionbetween perimortem and postmortem trauma (discussedbelow). With respect to trauma analysis in abuse cases,the comprehensive documentation of skeletal trauma(healed and unhealed) in the clean and processed bonehas lead to more denitive assessments of trauma tim-ing, critical to dening whether abuse is substantiated.

Trauma analysis and taphonomy: Conjoined twins

In the descriptions of trauma analysis above, it isassumed that the defects under examination resultedfrom intentional human intervention. We described ear-lier how the changes in biomechanical properties experi-enced by bone as it degrades aid in the assessment ofthe forensic signicance of a bone defect. This criterionis useful in determining forensic signicance of thetrauma on the basis of fracture timing. Those defectsinicted on fresh, highly organic (perimortem) bone aremore likely to have a forensic value than those inictedon dry bone (postmortem fractures, in the anthropologi-cal sense). However, forensic signicance does notdepend solely on defect timing. There are multiple natu-ral agents that can alter the human remains after theyare placed at the scene, including scavengers, humans,and environmental factors (water, temperature, soilcharacteristics and slope, sunlight, etc.).As stressed above, the key element to explain the

advantages of the anthropological approach to traumaanalysis is that the study and correct interpretation ofall of these factors (including the biochemical changeslinking bone degradation and biomechanics) does not fallwithin the eld of expertise of forensic pathology, butrather pertains to forensic taphonomy. Even more impor-tantly, the data necessary for the interpretation of all ofthese elements do not come exclusively from the humanremains, but also from the context in which they arefound, and require careful archaeological recovery.

PUTTING IT ALL TOGETHER

The following will highlight key new areas of forensicanthropological research where the intersection oftaphonomy, archaeological recovery, trauma analysis,and new quantitative methods has both expanded therange of questions to be answered by forensic anthropol-ogists, and fundamentally changed the analytical frame-work from which the classic questions are approached.

New perspectives on human rights cases andmass fatality incidents

The benets of a forensic taphonomic mindset withregard to what is expected of the data collected, andaffecting how they are collected, are certainly relevant tocases involving single or small numbers of individuals inoutdoor contexts, but are also well documented in newarenas only recently populated by forensic anthropolo-gists: human rights investigations (HRI) and mass fatal-ity incidents (MFI).

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Modern, scientic HRI trace back to the work of ClydeSnow and the Argentinean Forensic Anthropology teamearly in the 1980s (Doretti and Snow, 2003, and refer-ences therein). In spite of the clear and sound forensicscope of the pioneering Argentinean team, other earlyefforts at recovering HRI victims from mass graves weresoon focused on what was termed humanitarian efforts(Steadman and Haglund, 2005), in which victim identi-cation was the primary and almost exclusive focus. How-ever, quickly removing victims from mass graves inorder to speed victim identication and restitution (e.g.,Williams and Crews, 2003) ies in the face of the letterand spirit of the modern human rights concept (Dorettiand Snow, 2003; Dirkmaat et al., 2005). This is becausethe forensic value of the remains is greatly diminishedby the absence of the appropriate contextual informa-tion, which, in turn, adversely affects subsequent prose-cutorial efforts. Recently, the proper archaeological re-covery of mass graves (assisted by the latest technologi-cal advances in spatial data collection and analysis) haspermitted forensic taphonomic reconstructions of eventssurrounding the emplacement of the victims, establishedspatial patterning of the evidence, and assisted in thesorting and positive identication of commingledremains (Schmitt, 2002; Dirkmaat et al., 2005; Tuller etal., 2008). Further, the application of new techniques inthe analysis of human skeletal trauma and quantitativemethods in the analysis of the skeletal material(described above) solidies the forensic value of this evi-dence.Recent advances in quantitative methods derived from

modern populations (especially Fordisc) have benetedthe analysis of victim remains (often severely frag-mented and commingled) in large scale MFI (Sledzik,1996, 1998; Saul and Saul, 1999, 2003; Dirkmaat andMiller, 2003, Sledzik et al., 2003; Adams and Byrd,2008). However, it is only recently that advances in therecovery of evidence associated with the disaster site(bombing or plane crash) have been implemented.Archaeological documentation and recovery methodsadapted to large-scale mass disaster scenes and utilizingtechnological advances in spatial and contextual datacollection have been shown to outperform traditionalscene recovery protocols, not only in terms of the amountof evidence and information recovered, but also reducingscene processing times by almost one half (Dirkmaat andHefner, 2001; Reineke and Hochrein, 2008).

Case in point: Recovery of the fatal re victim

Perhaps the best illustration of the intimate, almostinextricable relationship between forensic taphonomy,archaeology, and bone trauma, and the resulting per-spectives, goals, objectives, data collection, and analyti-cal techniques inherent in the new forensic anthropology,is achieved through a discussion of another area of for-ensic investigation in which forensic anthropologists nowplay an important role: the analysis and interpretationof fatal re scene victims.Fire is a powerful and extreme taphonomic inuence

that can damage, alter, or destroy bone and associatedevidence (Mayne Correia, 1997; Mayne Correia andBeattie, 2002), and is consequently a common means ofconcealing evidence of a crime (Schmidt and Symes,2008). Since re often results in extensive damage, oralmost complete destruction of soft tissues, forensicanthropologistswith their expertise in examining bone

tissuesare frequently asked to take part in fatal reinvestigations.Put simply, there are two primary goals for the foren-

sic anthropologist to accomplish at these scenes. Therst is identifying the remains, both at the anatomicaland the individual level. The anatomical level refers tonding and identifying all of the individual bone ele-ments and fragments at the scene. The individual levelmeans assessing the number of victims and solving com-mingling issues if multiple individuals are involved. Thesecond primary goal is to distinguish perimortem bonetrauma from heat-induced bone alteration. Theextremely modied conditions of fatal re scenesseverely compromise and make difcult these goals, pro-viding an excellent illustration of the tightly knit rela-tionship between taphonomic inuence, scene recovery,and laboratory analysis of the remains.Victim remains at fatal re scenes are typically more

difcult to detect, recover, and handle (Dirkmaat, 1991,1998b; Mayne Correia, 1997; Mayne Correia and Beattie,2002). All of the burned materials at the scene, includingbiological tissue, are often modied to a similar appear-ance, and bones, in particular, become discolored, brittle,and highly fragmented. As a consequence, these remainsare often missed, disturbed, altered, or even destroyedduring scene processing utilizing existing protocols.The added postmortem fracturing, fragmentation, and

bone loss resulting from currently employed recoverytechniques hinder the already difcult task of autopsyand laboratory analysis of burned human remains.Establishing the number of victims and solving commin-gling issues in these cases will be more difcultand,arguably, impossible in some casesif skeletal elementsare missed, mixed, or further altered during the recov-ery. These problems are particularly acute for bonetrauma analysis, as its most immediate goal is distin-guishing perimortem (forensically signicant) trauma,from postmortem (not forensically signicant) alteration.The substantial addition of trauma features created byre and then recovery can result in a daunting analyti-cal task.For example, it is difcult to detect and characterize

atypical, potentially forensically signicant trauma if theextent of exposure of individual portions of the body tore is unknown (Symes et al., 1999, 2008). Exposure fac-tors will depend on the location and body positioning atthe scene, information that can only be retrievedthrough careful recovery and documentation (includingcareful mapping) at the scene (Dirkmaat, 1991, 1998a).The homogeneous coloration of the remains and theirsurroundings make mere scene photographs inadequatefor the task.

DISCUSSION

After reviewing the main trends and developmentsaffecting the eld in the last decades, it is time to returnto our original question: Is the current state and futureperspectives of forensic anthropology any better todaythan they were 20 years ago? Considering all of thedevelopments described above, the answer seems clearlyafrmative. The last two decades witnessed a diversica-tion of the goals and objectives of the eld, extendingand enhancing the role of forensic anthropologists incustomary forensic investigations. Analytical methodsand research sources in forensic anthropology have beenvastly improved through the rejuvenation of available

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comparative samples and an increased emphasis inquantitative methods, as opposed to the classical verbalmodel approach, which led to commonplace misconcep-tions. Even more important is the establishment of solidconceptual and methodological foundations to integrateand guide the future development of the eld. The adop-tion of paleontological, archaeological, and biomechanicalprinciples (not merely techniques), and transformed intoforensic taphonomy, forensic archaeology, and traumaanalysis, provides a conceptual framework much supe-rior and solidly entrenched in the natural sciences thanthe almost technical (when considered as an isolatedgoal) enterprise of biological prole estimation fromosteological remains.Iscans (1988) account of forensic anthropology as a

laboratory-based eld, squarely focused in providing evi-dence for victim ID from the naked bones, fails, not sur-prisingly, to describe the activities of modern forensicanthropologists. Answers to many more questions arerequired from forensic anthropologists nowa