encyclopedia of

Forensic Science revised EDITION

ENCYCLOPEDIA OF

Forensic Sciencerevised EDITION

suzanne Bell, Ph.D.Bennett Department of Chemistry,

West Virginia University, Morgantown

Foreword by

Barry A. J. FisherAmerican Academy of Forensic Sciences,

Past President, 19981999 Crime Laboratory Director,

Los Angeles County Sheriffs Department

preface by

Robert C. Shaler, Ph.D.Director, Forensic Science Program,

Pennsylvania State University

Encyclopedia of Forensic Science, Revised Edition

Copyright 2008, 2004 by Suzanne Bell, Ph.D.

All rights reserved. No part of this book may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying, recording, or by any information storage

or retrieval systems, without permission in writing from the publisher. For information contact:

Facts On File, Inc.An imprint of Infobase Publishing

132 West 31st StreetNew York NY 10001

Library of Congress Cataloging-in-Publication Data

Bell, Suzanne.Encyclopedia of forensic science / Suzanne Bell; foreword by Barry A. J. Fisher; preface by

Robert C. Shaler.Rev. ed.p. cm.

Includes bibliographical references and index.ISBN-13: 978-0-8160-6799-2 (acid-free paper)

ISBN-10: 0-8160-6799-6 (acid-free paper) 1. Forensic sciencesEncyclopedias. I. Title.HV8073.B425 2008

363.2503dc22 2008005862

Facts On File books are available at special discounts when purchased in bulk quantities for businesses, associations, institutions, or sales promotions. Please call our Special Sales

Department in New York at (212) 967-8800 or (800) 322-8755.

You can find Facts On File on the World Wide Web at http://www.factsonfile.com

Text design adapted by James Scotto-LavinoIllustrations by Sholto Ainslie

Photo research by Suzanne M. Tibor

Printed in the United States of America

VB Hermitage 10 9 8 7 6 5 4 3 2 1

This book is printed on acid-free paper and contains 30 percent postconsumer recycled content.

To my husband, Mike, and to my departed mother

thanks for all the years of faith and support.

Foreword ix

Preface xi

Acknowledgments xiii

Introduction xv

Entries AZ 1

Feature Essays:

Forensic Science and History 46

Classification, Identification, Individualization, and a Common Source

80

Myths of Forensic Science 89

DNA Typing and Privacy 109

Drug Testing in Sports 116

Careers in Forensic Science: A Reality Check 122

Contents

Learning from Tragedy: Forensic Science and Terrorist Attacks 128

History of Fingerprints: Stay Tuned! 150

The Future of Forensic Science 161

Fiction and Forensic Science 190

Identification of the Dead: Forensic Science and Mass Disasters 200

TWA Flight 800: Mass Disaster and the Interface of Criminal Investigation, Forensic Science, and Forensic Engineering

242

The Future of Lie Detection 287

Forensic Science and Juries: How Complex Is Too Complex? 328

The Top Ten Cases in Forensic Science 357

Appendixes:

Appendix I Bibliographies and Web Resources

367

Appendix II Common Abbreviations and Acronyms

373

Appendix III Periodic Table of the Elements

377

Index 379

ix

Hardly a week passes when I do not receive a phone call or e-mail from a col-lege or high school student asking about careers in forensic science or wishing to interview someone for a class report they must do on forensic science. To be sure, much of this interest is a result of nearly a decade of media hype from such television programs as CSI, Forensic Files, and dating all the way back to the O. J. Simpson trial coverage. But for whatever reason, there is a genuine fascination about the subject. What is forensic science? What sort of academic preparation do I need to enter this field? Where do I turn for answers?

Crime laboratories and medical examiner/coroners offices play a vital role in our nations criminal justice system. Forensic science brings science, medicine, and technology to bear in criminal investigations and helps police and prosecutors do their jobs better. Those who work in this field have university degrees in chemistry, biology, and the like.

Suzanne Bells Encyclopedia of Forensic Science, Revised Edition, an excellent reference, again addresses many of the questions people have who are considering careers in this field. The encyclopedia is also a wonderful resource for the general public who is simply interested in the subject matter. Arranged as a collection of literate entries enhanced by 14 relevant essays, Bell covers the expansive area of forensic science well. She provides readers interested in forensic science with a single source that is easy to understand, accessible, and very well written.

The book is organized in alphabetical orderA through Zwhereas entries and their cross-references that have to do with the subject are eas-ily found and explained along with essays on a number of subject areas. She has also done a fine job in bringing the volume up to date with both new and revised entries to be as complete a reference as possible.

For those seriously considering forensic science as a career, I also recommend one of the many fine professional organizations in the area. Membership information is easily found on the Web. Three of the many fine organizations are the American Academy of Forensic Sciences, the International Association for Identification, and the National Association of Medical Examiners. These are but a few of the other resources available.

Professor Bells Encyclopedia of Forensic Science, Revised Edition is an excellent start to begin your exploration of this intriguing field of study.

Barry A. J. Fisher American Academy of Forensic Sciences President, 19981999

Crime Laboratory Directory Director Los Angeles County Sheriffs Department

Foreword

xi

Young students nationwide are increasingly attracted to what might argu-ably be the new wave profession: forensic science. Whether this interest stems from the plethora of television shows, such as the numerous docu-mentaries and docudramas currently broadcast, or from an inherent inter-est in forensics, students are flocking to the profession in unprecedented numbers. Universities offering forensic science degrees are springing up throughout the country to meet the demand, and high school science teach-ers are adding forensic courses to their science curricula. Forensic science touches the everyday world in multiple ways, so it stimulates impression-able young minds and propels students toward careers in forensic-related professions: law enforcement, the law, medicine, nursing, and science.

Re-creations of the practice of forensic science on television programs such as C.S.I. and Forensic Files also affect events in the real world. For example, jurors are demanding more science in the courtroom, a phenom-enon known as the C.S.I. effect, which forces prosecutors and defense attorneys to consider how the science will affect their cases when going to trial. Law-enforcement and legal officials working in the criminal justice system are subjected to forensic practice almost daily, and many struggle to understand the science of forensics without having a scientific background.

Thus, many individuals and organizations in our complex modern soci-ety, because of an interest in forensics, career aspirations, or professional practice need an authoritative source of forensic information. Certainly many forensic-science textbooks are readily available, but these are mostly written for practicing professionals or college-level students and do not con-sider the nonscientist. Such a resource should be written by a forensic scien-tist, an educator who understands the nuances of forensic practice, its legal implications, and relationship to our criminal justice system. The resource must be comprehensive and explain the science behind forensic practice accurately but at a level that a nonscientist easily comprehends.

Suzanne Bells Encyclopedia of Forensic Science, Revised Edition is such a resource: It is a comprehensive, factual reference for anyone inter-ested in learning about topics in forensic science from a lay perspective. Like any encyclopedia, the book lists subjects alphabetically, is extensively cross-referenced, and provides references for further reading. For example, Bell cross-references shotguns under firearms, where she writes about various types of firearms and includes a history of firearms. Under FBI, she gives a brief history of the agency. In another section she discusses how the scientific method relates to forensic scientific investigations.

PreFaCe

The book also includes helpful Feature Essays, sprinkled through-out the encyclopedia, that illustrate how contemporary topicsdrugs, fingerprinting, sports, etc.relate to forensic science. Dr. Bell pulls no punches when candidly discussing confounding issues in modern forensic science, such as ethics, bias, and individualization versus identity.

An interesting aspect of the encyclopedia is her treatment of histori-cally famous cases. In the Lindbergh kidnapping and murder case of the 1930s, for example, she explains how questioned documents and tool-mark examinations helped to prove Bruno Hauptmanns guilt. In the Sam Sheppard murder case of the 1950s, Bell explains why Dr. Paul Kirk believed Sheppard was innocent, based on bloodstain patterns he analyzed at the crime scene. She mentions the pioneers of forensic science in the encyclopedia and the role they played in shaping contemporary forensic science. She dives into the influence of recent court decisions, such as the Daubert decision in 1993 that defined the admissibility of scientific evi-dence in federal courts.

In an era where the word forensic seems ubiquitous and most every profession has or wants a forensic bentforensic meteorologists, veteri-narians, kinesiologists, accountants, and othersit is reassuring that the core disciplines employing the application of the basic sciences (chemistry, physics, and biology) to the analysis of physical evidence is still alive and covered extremely well by Bell in the Encyclopedia of Forensic Science, Revised Edition.

Robert C. Shaler, Ph.D. Pennsylvania State University

Professor, Biochemistry and Molecular Biology Director, Forensic Science Program

Retired Director of the Forensic Biology Department Office of Chief Medical Examiner, City of New York

xii Preface

xiii

aCknowledgments

Forensic science is a field growing larger every day and no one per-son could ever hope to grasp it all. This book would have been impos-sible without the assistance of dedicated and generous forensic scientists who volunteered their time, advice, expertise, and library of photos to this effort. Aaron Brunedelle (Idaho State Patrol and later Washington State Patrol and Arizona agencies) supplied many fine images, particu-larly of firearms evidence and microscopic images. Chet Park, also of the Idaho State Patrol, also provided images. Art Craig of the New Mexico Department of Public Safety (NMDPS) took photos of presumptive chemical tests and shared good times with me while we worked together in Santa Fe in the 1980s. I owe a debt to many New Mexicans in the State Patrolpast and presentfor hiring me there and letting me earn my forensic wings. Other colleagues who graciously supplied images are Heather Schafstall (Oklahoma State Bureau of Investigation) and Bill Schneck of the Washington State Patrol and Microvision. My photo researcher, Ms. Suzanne Tibor, located a number of commercial images, and I greatly appreciate her efforts.

Many members of the American Academy of Forensic Sciences (AAFS) provided hours of time and assistance. First and foremost, I am indebted to Dr. R. E. Gaensslen of the University of Illinois (Chicago) not only for reviewing my DNA entries, but also for starting me in this direction when I was a graduate student. Teacher, scholar, and gentlemanno one could dare hope to find a better mentor. I also wish to thank Jim Hurley and the Executive Council of the AAFS for assisting in finding reviewers and ensuring that this book was the best it could be. Barry Fisher, Max Houck, and Dr. Bruce McCord were gracious enough to review the text in the first edition on behalf of the Academy and to provide feedback and suggestions. Reviewers are often unsung heroes, and I extend a hearty thanks to all for their time and effort. A special thanks to Dr. Robert Shaler of Pennsylvania State University for career support and the preface.

Finally, I wish to thank the wonderful folks at Facts On File, particu-larly Frank K. Darmstadt, executive editor, who is a joy to work with and the walking definition of professional. I am proud to be associated with a company that is dedicated to education, particularly of young people. I am grateful to have been given the opportunity to produce this book under their expert guidance.

xv

IntroduCtIon

The two words forensic and science each relate to the common theme of truth, either spoken or seen. The word forensic can be traced to the Latin forum, or in the public. The definition is roughly translated as to speak the truth in public. In the modern world, this extends to speaking the truth in court, todays equivalent of the forum. Thus, the role of sci-ence is to help society define what is fact; the role of forensic science is to help the legal system define it.

As a recognized scientific field, forensic science is a relative newcomer, yet it represents a natural expansion of existing disciplines such as chemistry, biology, geology, medicine, anthropology, engineering, and many others. The scope and depth of forensic science grows daily as new technologies are dis-covered and as our society becomes more dependent on the judicial system to solve disputes. At the same time, the publics fascination with forensic science is surging as evidenced by the success of movies, novels, and television shows with forensic themes. Recently, the CBS television show C.S.I. has been among the highest rated dramas, resulting in a 2002 spin-off entitled C.S.I.: Miami and later, C.S.I.: New York. Novels such as those authored by Kathy Reichs and Patricia Cornwell top best-seller lists, and detective and police movies routinely integrate forensic science into their plot lines. Coupled to these fictional portrayals are real events such as the attacks of September 11, 2001, the anthrax mailings, the sniper attacks around Washington, D.C., in late 2002, terrorist attacks in Madrid and London, and the 2004 tsunami, in which forensic science was a highly publicized component.

With high levels of public exposure and awareness, particularly through entertainment, comes the need for public education. There is a danger that media coverage and fictional portrayals of forensic science can lead people to exaggerate and misunderstand the role, capabilities, and limitations of forensic science. This growing gap between forensic fiction and forensic sci-ence served as a primary motivation for this project, which grew from my experiences as a forensic laboratory scientist, researcher, and forensic sci-ence educator. Encyclopedia of Forensic Science represents my small contri-bution toward linking public perception of forensic science to its reality.

Encyclopedia of Forensic Science gathers the core topics of forensic science into one comprehensive volume and provides an overview of each. Interested readers will find resources in the references and appendixes for further investigation of topics of interest to them. These references range from textbooks to articles in professional journals, all of which are available at or through public or college libraries. The encyclopedia is richly illustrat-ed with drawings and figures and supplemented with photographsmost

supplied by working forensic scientists in many different organizations. A color insert containing selected photographs provides additional detail in areas such as firearms, toolmarks, and DNA analysis. Fourteen essays inter-spersed throughout the encyclopedia describe how forensic science relates to areas such as drug testing in sports, privacy concerns, and the interface of forensic engineering and forensic science. One essay, The Top Ten Myths of Forensic Science, deals directly with misconceptions about forensic sci-ence. In a larger sense, the intent of the encyclopedia is to provide students, teachers, and the public with a comprehensive and reliable reference that shows forensic science as it really is, devoid of romance, glamour, and hype.

TARGETAUDIENCEANDREADERS

Encyclopedia of Forensic Science is geared to reach a wide audience rang-ing from students to working professionals. At the high school and college level, the encyclopedia can serve as the starting point for class projects or career research. General readers can use the encyclopedia to learn about timely topics and issues relevant to forensic science. Working profession-als and forensic laboratories will find the encyclopedia a useful addition to their libraries, a quick and easy source of information on more than 600 forensic science topics.

ORGANIZATIONANDCONVENTIONS

The International System of Units (SI) conventions have been followed in this book, the only exceptions being in entries or topics in which forensic scientists conventionally use other units. A Periodic Table of the Elements is provided in Appendix III, and references to these elements are provided as both names and symbols (for example, arsenic and As). Appendix II comprises an extensive list of the common abbreviations used in forensic science. For alphabetical ordering, the different areas of forensic science are listed in the order of their subject area. For example, forensic anthro-pology can be found under anthropology, forensic. Similarly, bio-graphical or other named entries are ordered based on last name. Thus, a discussion of the O. J. Simpson case is listed under Simpson, O. J.

TERMINOLOGYINANEVOLVINGWORLD

As this volume went to press, issues were being debated within the forensic science community and the courts concerning the significance and unique-ness of pattern evidence such as toolmarks and bite marks, finger-prints, and dna evidence. For example, successful dna typing of 13 codis loci can result in a probability of duplication that, while not zero, is astoundingly small. However, whether it is correct to say that such a com-bination of DNA types can be considered unique (individualized) has not been fully resolved. Similar debates about the uniqueness of fingerprints and impression evidence continue. An understanding or qualifying statement such as unique to reasonable degree of scientific certainty is often appro-priate and should be understood by the reader even if not stated explicitly.

Finally, the reader should know that every reasonable effort was expended to find reliable, peer-reviewed sources and to present a techni-cally correct and balanced treatment of controversial subjects and cases. Two distinguished members of the American Academy of Forensic Science have reviewed the encyclopedia, while many more assisted with individual entries. However, these entries are not intended as a primary reference, but rather as an overview and gateway to the wealth of information avail-able on the fascinating field that is forensic science.

xvi Introduction

entrIes aZ

AABO blood group system Thefirsthumanblood group systemdiscoveredandthefirstusedinforensicserology.AlthoughABOtypingwasanindispensabletoolinforensicserologyfordecades,DNA typinghaslargelyreplacedbloodgrouptyping.

TheABOsystemconsistsofantigensfoundonthesurfacesofredbloodcells(alsocallederythrocytesandcommonlyabbreviatedRBCs)andcorrespondinganti-bodies in the serum.Karl Landsteiner discoveredtheABObloodgroupsystemin1900andforaquar-terofacentury,itwastheonlyoneknown.Confusionover naming conventions continued until 1941, whenthe U.S. military adopted the ABO standard. By the1960s ABO typing of bloodstain and body fluidevidencewascommonplaceinforensiclaboratories.

TheABOsystem is apolymorphicbloodgroupsystem, meaning that the antigens (and correspond-ingantibodies)havemorethanoneobservablevariant(phenotypes or type). These variants are summa-rizedintheaccompanyingfigure.Intheserumportionofblood,apersonwillhavetheantibodiesassociatedwith the antigen not found on the RBC surface. Forexample, someonewithType B blood has B antigenson the surface of their RBCs and anti-A antigens intheirserum.Forbloodtransfusions,peoplewithTypeAB blood are considered to be universal recipientssincetheirserumdoesnotcontainanyanti-Aoranti-Bantibodies.Conversely,peoplewhoareTypeOareuniversaldonorssincetheirRBCshaveneitherantigen.There is also anHantigen, and an anti-HantiserumthatwillcauseOcells toagglutinate (seebelow),andsothenotationABHbloodgroupsystemissometimes

used.TherearealsosubgroupswithinTypesA,B,andAB,butthesearenotroutinelyusedinforensicwork.IntheU.S.population,theapproximatefrequenciesofthetypesare

TypeA42percent TypeO43percent TypeB12percent TypeAB3percent

Inaddition,alargepercentageofpeople(~80per-cent)aresecretors,meaningthattheantigenspresentintheirbloodarealsofoundinotherbodyfluidssuchassaliva.

When antibodies react with corresponding anti-gens on theRBC surface, the cells clump together ina reaction called agglutination, which is illustratedin the figure. For example, if RBCs with A antigenson the surface (TypeAblood) aremixedwith serumcontaining anti-A antibodies (Type B blood), agglu-tination results. This was the process that, prior toLandsteiners discovery, caused many people to dieafter receiving blood transfusions. In recognition ofhislife-savingdiscovery,hereceivedtheNobelPrizein1930.

Differenttestsweredevelopedtotypewholebloodbeginningin1915withtheLattescrusttest.Thistestis applied to the serumandworks by adding knownblood cell types to the unknown serum and lookingfor agglutination. In 1923, Vittorio Siracusa devel-opedtheabsorption-inhibition test,whichdetectsthe type of antigens on the RBC surface. absorp-tion-elutionfollowedin1930,andallofthesetests,

plusmodificationsandvariants,havebeenappliedinforensicserology.

Typingofbloodandbody fluids in forensicworkusually involves stains rather than whole blood, andthe stained material may be old and may have beensubject toadverseconditions.Therearenowholeredbloodcellsleftindriedstainssincethecellmembranesrupture when dried. However, the surface antigenssurviveandaremorestablethantheserumantibodies.Absorption-elution typing can be performed on verysmall samples (threadsor fibers)andhasbeenshowntowork on stains that are 10 years old and older. Itisalsomoresensitivethanabsorption-inhibitionandisusuallythemethodofchoice.

A and B antigenic substances are common innature, found in plants, animals, and insects. Thisintroduces the danger of false positive results ifother biologicalmaterial has contaminated a forensicsample.false negativesarepossibleifthesamplehas

been subject to harshweatheringor is very old.Thisillustratesacommonprobleminforensicscience:oftenitisnottheaccuracyandprecisionofatestingmethodthatdeterminesitssuccess;rather,itistheconditionofthesample.Bloodstainsarehardertotypethanwholeblood; old, weathered, or damaged bloodstains aremoredifficultorimpossibletotype.

See alsoblood.

Further ReadingDeForest,P.R.,R.E.Gaensslen,andH.C.Lee.Chapter9:

Blood. InForensic Science: An Introduction to Crimi-nalistics.NewYork:McGraw-Hill,1983.

Saferstein, R. Forensic Serology. In Criminalistics: An Introduction to Forensic Science. 7th ed. Upper SaddleRiver,N.J.:PrenticeHall,2001.

absorption-elution and absorption-inhibition testsTwotests thatareusedtotypebloodandbody flu-ids for ABO and other blood group systems.Absorption-inhibitionwas developed in 1923 in Italyby Vittorio Siracusa, and absorption-elution fol-lowedinthe1930s.Manymodificationsandvariantshave appeared, and the general procedureshavebeenapplied to other blood group systems. Although redbloodcellsrupturewhenabloodstaindries,theAandBantigens thatarepresentonthecell surfacepersist.

The process of agglutination, in which red blood cells clump in the presence of corresponding antibodies. For example, if Type A serum (containing anti-B antibodies) is mixed with Type B red blood cells, the B antigens will bind with the anti-B antibodies and form linked clumps of cells. The color insert contains a pho-tograph showing agglutination.

Components of ABO blood types. The antigens, shown as tri-angles, are found on the surface of the red blood cell (RBC), whereas antibodies are found in the serum. A person with Type A blood has A antigens and antibodies to B antigens (anti-B).

absorption-elution and absorption-inhibition tests

Asaresult,thesetestsworkonwholeblood,bodyflu-ids(assumingthepersonisasecretor),andinstainsofanyofthosefluids.

Absorption-inhibition works by reducing thestrength of an antiserum based on the type andamountofantigenspresent inthestain.Forexample,if the bloodstain comes from a person with Type Bblood, the stainwill containB antigens. If an anti-Aantiserumof a known strength is added to the stain,nothing will happen. If anti-B antiserum is added,some of the antibodies will bind to the B antigens,reducing the strength of the original antiserum. Thisreduction of strength is the inhibition for which the

test is named. Although effective, absorption-inhibi-tionislesssensitivethanabsorption-elutionandthere-forerequireslargersamples.Thispresentsaproblemifthestainisverysmallortheamountofsampleislim-ited,asituationoftenencounteredinforensicanalyses.Consequently, absorption-elution is more common inforensicapplications.

The absorption-elution test is illustrated in theaccompanying figure, using a stain of Type B bloodas the example. Antiserum containing both anti-Aand anti-B is added to the stain. Anti-Bwill bind totheBantigensandwillremainbehindwhenthestainis rinsed with cold saline. The stain is then heated,breaking thebondbetween theBantigensandanti-Bantibodies.Thesolutionintowhichtheanti-Bantibod-ieshaveelutedisthensplit inhalf.Tooneportion,Acells are addedand toanother,B cells.Agglutination(clumping)willbeobservedwiththeBcells,confirm-ing the type of the original stain. Absorption-elutiontechniquesworkonsamplesas smallasa single fiberand have been shown to work on stains that are adecadeoldorolder.Absorption-elution is rarelyusednow given thatDNA typing has essentially replacedtraditionaltypingtechniques.

See also ABO blood group system; blood; body fluids.

Further ReadingSaferstein, R. Forensic Serology. In Criminalistics: An

Introduction to Forensic Science. 7th ed. Upper SaddleRiver,N.J.:PrenticeHall,2001.

absorption spectrum Agraphthatplotstheabsor-bance of electromagnetic radiation (emr) by aselected material as a function of the wavelength ofradiation. Although commonly associated with thevisibleportionoftheelectromagneticspectrumwherecolorscorrelatewithwavelengths,anabsorptionspec-trumcanbegeneratedinanyspectralrange.Inforen-sic analysis, the most common types of absorptionspectrausedarethoseinthevisiblerange(VIS),ultra-violet(UV),andinfrared(IR).Forexample,anabsorp-tion spectrum of adye can help characterize fibersand inkswhile an infrared absorption spectrum is astandardcomponentofdrug analysis.

Instrumentation (generically called spectropho-tometer or spectrometer) isrequiredtogenerateanabsorptionspectrum.Forcreatingaspectrumofamate-rialintheUV/VISrange,theinstrumentiscalledaUV/VIS spectrophotometer, whereas an instrument that

Depiction of the steps in an absorption-elution test for ABO blood type. In this example, the bloodstain is Type B, which would con-tain B antigens. As a result, the stain will react with anti-B serum. After rinsing and elution, the eluted solution will contain the lib-erated anti-B antibodies that will agglutinate with B cells.

absorption spectrum

worksintheinfraredrangeiscalledanIRspectropho-tometer.Ingeneral,thefunctionoftheinstrumentistobreakupradiation into individualwavelengths thatarethen directed at the sample. The amount of energyabsorbedbythesampleateachwavelengthisplottedtoproducethespectrum.Differentinstrumentdesignsexistandmanytechniquescanbeusedtogenerate thespec-trum,buttheresulttypicallyisaplotoftheabsorptionversuswavelength,asillustratedinthefigureabove.Thepattern of the spectrum provides valuable chemicalinformationaboutthesamplefromwhichitwasgenerat-ed,andinsomecasesissufficientbyitselftoidentifythesubstancespecificallyandunequivocally.

accelerant Inarson cases,anaccelerant is the flam-mablematerialthatisusedtostartthefire.Accelerantscanbesolids, liquids,orgases,withgasolinebeingthemost commonly used. Solid accelerants include paper,fireworks, highway flares, and black powder. Butane(cigarette lighter fuel), propane, and natural gas areexamplesofgaseousaccelerants,whichdonotleaveanyresidueatafirescene.However,gasesmustbecontainedandtransported,soseveredgaslinesorspentcontainersserveascriticalphysical evidenceinsuchcases.

Liquid accelerants fall into two broad categories:petroleumdistillates,whichincludegasolineandotherpetroleumproducts; andnonpetroleumproducts suchasmethanol,acetone(usedinnailpolishremover),andturpentine.

Petroleumdistillatesarederivedfromcrudeoilandare also called hydrocarbons or petroleum hydrocar-bons. Incrudeoil,volatilityof the individualcompo-nentsrangefromextremelyvolatilesubstancessuchaspropane(agasatroomtemperature)toasphalt,whichremainssolidevenathightemperatures.

Petroleumdistillatessuchasgasolineandkerosenearenot singlehydrocarbonsbutmixturesofdifferentcomponents with similar volatilities. The volatilityof an accelerant is an important consideration in thecombustion process, determining howmuch residuewill be left and how quickly it will evaporate afterthe fire isout.Related tovolatility is the flashpoint,definedas thetemperatureatwhicha liquidwillgiveoff enough vapor to form an ignitable mixture. Forgasoline, the flash point is -50F (-45.56C). TheNationalFireProtectionAssociation(NFPA)definesaflammableliquidasonewithaflashpointoflessthan140F(60C).

Absorption spectrum is a plot of wavelength of radiation versus the amount of that radiation absorbed by the sample being ana-lyzed. The higher the point (here, the greater the absorbance), the greater the amount of radiation absorbed.

Collection of residual accelerants from evidence collected at an arson scene. The debris is placed in a sealed paint can such that empty headspace remains above it. When the can is sealed, the volatile accelerants continue to evaporate, and the vapors will collect in the headspace, which can then be sampled for further analysis.

accelerant

Basedonvolatilityandmolecularstructure,petro-leum distillates are often divided into the followingcategories:

Category Example

Light petroleum distillates (LPD) Propane, butaneMedium (MPD) Paint thinnerHeavy (HPD) Kerosene, diesel fuelAromatics Benzene, toluene, xylenesMixtures Gasoline

Aromatic hydrocarbons have uniquemolecular struc-turesandwereoriginallynamedbasedontheirdistinc-tivesmell.Aromaticssuchasbenzeneandtoluenearefoundingasoline.

Atafirescene,thepresenceofaccelerantscanbedeterminedusingseveralprocedures includingtraineddogs, chemical color tests, and portable instrumentsandsensors.Materialssuchaswoodandcarpetabsorbliquid accelerants, so samples of these materials canharborvaluableevidence.Itisimportantfortheinves-tigatortocollectcontrol samplessincecarpetsandothersyntheticmaterialscan interferewithor leadtofalse positivesduring laboratoryanalysis.Evidencefrom the scene is usually collected in glass jars ormetallic paint cans that are tightly sealed to preventvapors from escaping.As shown in the figure on theprevious page, once the can is sealed, any volatileaccelerantspresentwillcontinuetoevaporateintotheheadspaceabovethedebris.

Theprimarytoolusedtodetectandidentifyliquidaccelerantsisgas chromatography(gc)coupledtoeitheraflame ionization detector(fiD)oramass spectrometer(ms).Analysisusingeitherinstrumentproduces an output that is distinctive for most com-mon petroleum distillates. Patterns are identified bycomparison to standards of known composition. Thepatternsobtainedfromevidencecanbe influencedbyweathering and by microbial activity, particularly ifthesampleisonsoilorvegetation.Weatheringoccursaslighter(morevolatile)componentsoftheaccelerantevaporate,andthelongerthesamplesitsbeforecollec-tion,themoreseveretheweatheringeffects.

SamplesarepreparedforintroductionintotheGCusingseveralmethods:

1. Cold headspace:Thecanispuncturedandasyringeis used to withdraw a headspace sample that isinjectedintotheGC.

2. Heated headspace:Priortosyringeintroduction,thecanisheated.

3. Extraction:Theaccelerantisextractedfromthesam-pleusingasolventsuchascarbondisulfideorsteam.SmallportionsoftheextractareinjectedintotheGC.

4. Purge-and-trap: Inlet and outlet holes are put inthe can lid. A stream of filtered air is pumped inthrough the inlet and a charcoal trap is placed ontheoutlet.The canmaybeheated, andvapors aretrapped on the charcoal. The trapped compoundscanbe removedusingheat (thermaldesorption)orsolventextraction.

5. Charcoal strip/solid phase microextraction (spme):Acharcoalstriporotheradsorptivematerialis lowered into the canor placedon an inlet drilledintothecan.Avacuumcanbeusedtodrawsamplethrough the trap or a stream of filtered air can bepumped into thecan to forceheadspace to flowoutthroughthetrap.Thecanmaybeheated,withather-mometerinsertedinthecantomonitortemperature.

Insomecases, thepresenceofaflammablemate-rial inagivenarea is tobeexpectedandmaynotbeassociatedwitharson.Forexample,ifafireisstartedin a garagewhere a car is parked and gasoline pow-eredequipmentsuchasasnowblowerorlawnmoweriskept,thegasolineassociatedwiththetoolsorcarisconsidered to be an incidental accelerant that wouldnormallybepresentinthearea.

See alsofire investigation; incendiary devices.

Further ReadingMidkiff, C. Laboratory Examination of Arson Evidence.

InMore Chemistry in Crime, From Marsh Arsenic Test to DNA Profile. Edited by S.M.Gerber andR. Saferstein.Washington,D.C.:AmericanChemicalSociety,1997.

accidental characteristics Marks that appear oncertain types of evidence such as tires, bullets, orshoes that do not appear on all such evidence. Forexample, the soles of shoes are mass-produced froma mold, and so all soles made from the same moldshould have the same pattern. An accidental markcouldappearononesole if itwasaccidentallycutatthe factoryor themoldwas somehowdamaged.Themarks that result are not supposed to be there, buttheirpresencecanbeinvaluabletoaforensicanalysisfor thatreasonthemarksdifferentiate thatparticu-larshoe(orgroupofshoes)fromthebatch.Accidentalcharacteristicscanalsoplayaroleinquestioneddocu-mentevidence.Rollers inprintersandcopierscanbe

accidental characteristics

scratchedorgouged,resultinginamarkonthepaperthat can be used to link that document to a specificrollerandthusaspecificprinter.

See alsowear patterns.

accident reconstruction See traffic accident reconstruction.

accounting, forensic The application of account-ing techniques to criminal and civilmatters. Forensicaccountantsstudyfinancialrecordsandotherfinancialevidence,prepareanalysesandreports,assistininves-tigation,and likeanyother forensicprofessional, canbecalledontorelatefindingstoacourtoflaw.Mostoften,forensicaccountantsareCPAs(CertifiedPublicAccountants) that specialize in fraud or other inves-tigative accounting. Fraud accounting and forensicaccountingareoftenreferredtounderthegeneraltermlitigation support. Inaddition to litigation support,forensicaccountingcanbeinvolvedincorporateinves-tigations,insuranceclaims,andregulatorycompliance.Forensic accounting and forensic computing oftenoverlap. Financial institutions, insurance companies,and governmental agencies, notably the IRS (InternalRevenueService),fBi,GAO(GovernmentAccountabil-ity Office), and SEC (Securities and Exchange Com-mission),employforensicaccountants,asdosomelawenforcementagencies.Mattersinvestigatedusingforen-sic accounting and related techniques include (amongmanyothers)arson,bankruptcy,checkforgery,checkkiting, computer fraud, credit card fraud, contesteddivorcesettlements,embezzlement,financingofterror-ism, softwarepiracy, tax fraud,andevendivorce set-tlements ifabusiness is involved.RecentexamplesofinvestigationsinwhichforensicaccountingwascrucialincludetrackingthemoneyusedtofinancetheattacksofSeptember11,2001,andthebankruptcyofEnron,aHouston-basedenergytradingfirm.TheAssociationofCertifiedFraudExaminers (ACFE:www.acfe.com)certifiespractitionersinthefield.

Further ReadingBologna, G. J., and R. J. Lindquist. Fraud and Forensic

Accounting: New Tools and Techniques.2ded.NewYork:JohnWileyandSons,1995.

accreditation See American society of crime Laboratory Directors(AscLD).

acetone-chlor-hemin test (Wagenaar test) Oneof several chemical testsused to identifyblood.Like

many presumptive tests for blood, it works byformingdistinctivecrystalswithhemoglobinderiva-tives (hematin, hemin, and hemochromogen). Proce-dures for the test were published in 1935, and theyare fairly simple. A few drops of acetone (a com-mon ingredient innail polish removers) are added toa suspectedbloodstain followedbyadropofdilutedhydrochloric acid (HCl). If hemoglobin is present,characteristic crystals form,which are thenobservedunderamicroscope.

ACE-V An acronym for analysis, comparison, eval-uation, and verification. This is the process used bylatent fingerprint examiners to evaluate the pat-terns of latent fingerprints. The first step (analysis)involves studying the latent fingerprint to determineif it is suitable for comparisons.Todoacomparison,thelatentfingerprinthastobereasonablyclearandasufficient portion of the finger must havemade con-tactwiththesurfaceandleftanimpression.It isalsoimportanttobeabletotellwhatmadetheimpression,be it a finger, thumb, or palm. Once the examinerdeterminesthattheprintcanbecompared,theexam-iner selects what to compare it to, such as a sampletakenfromasuspectoraprintretrievedfromadata-basesearch.Comparisioninvolvesafeature-by-featureexaminationofeachandwillideallyresultinexclusion(theprintscouldnothavecomefromthesamepersonor common source) or indentification (individu-alization) that conclusively links the two comparedimpressions to the sameperson.The resultsmayalsobeinconclusive,acaseinwhichdefinititiveidentifica-tionorexclusioncannotbemade.Thefinalstepisver-ificationoftheresultsbyanotherqualifiedanalyst.

acid phosphatase (AP, ACP, EAP) See isoenzyme systems; semen.

acronyms SeeAppendixII.

adenosine deaminase(ADA)Seeisoenzyme systems.

ADME An acronym for the linked processes ofabsorption, distribution, metabolism, and excretionthatoccurwhenapersoningestsasubstancesuchasadrugorpoison.Themostcommonmodesofinges-tion encountered in forensic toxicology are swal-lowing,injection,inhalation,andabsorptionthroughthe skin. Once ingested, the material (also called a

accident reconstruction

xenobiotic)isabsorbedintothetissues.Ifthexeno-biotic is swallowed, this absorption usually occursin the digestive tract. The absorbedmaterial is dis-tributed throughout thebodyand tissuesdependingprimarilyonhowwater-soluble it is. Substancesaremetabolizedprincipally in the liver to formmetabo-lites thatmaybeexcretedorotherwisedeliminated.Somemetabolitesmaybelesswater-solublethantheoriginaland thuswill tend to linger in fatty tissues.Others may become volatile and can be eliminatedthroughbreath,whilestillothermetabolitesmaybefuthermetabolized.Forexample,heroinisanillicitdrug that can be ingested by swallowing, injection,orby smoking (inhalation).Once absorbedanddis-tributed to the bloodstream, heroin is metabolizedtoacompoundcalledmonoacetylmorphine,whichisitselfmetabolizedtomorphine.

See alsoalcohol; metabolism and metabolites.

adenylate kinase (AK) Seeisoenzyme systems.

adhesive tape Different types of tape (adhesive,electrical,masking,duct,andsoon)maybeinvolvedin a crime and become physical evidence. Forexample,tapemightbeusedtobindavictimormight

The stages of ADME

Ethanol is a small water-soluble molecule that is quickly absorbed in the digestive tract and distributed to tissues. In the liver, it is efficiently converted to acetaldehyde, which is excret-ed in the breath and urine. Some is exhaled in breath as ethanol, and some is metabolized to CO and exhaled. About 0 percent of the original ethanol is excreted in the urine unchanged.

adhesive tape

bewrappedaroundthehandleofatoolusedinabur-glary.Packingorcleartapemaybeusedtowrappack-ages containing drugs or bombs.Documentsmay befoundtapedtopackagesorotherdocuments.

Tapeconsistsofabackingmaterialtoppedwithapressure sensitiveadhesive.Thebacking canbemadeof a plastic polymer, cloth, or paper. The adhesivescanbecharacterizedusingmicroscopic,chemical,andinstrumental methods such as attenuated total reflectance (Atr) infrared spectroscopy (ir),a technique well suited for surface analyses. Otherinstrumental techniques used include gas chroma-tography/mass spectrometry(gc/ms)andultra-violet spectroscopy (uv/vis).Physicaldimensionsofthetapecanalsobeimportantforcomparisonandidentification;characteristicssuchaswidthandthick-ness can be used to reduce the number of possiblesourcesandmanufacturers.

Ifafragmentoftapeisfoundatascene,itmaybepossible through physical matching techniques tolinkthefragmenttothesourceroll,assumingthatthetapehasbeentornratherthancut.Tapeisalsoexten-sivelyused tocollect evidence suchashairs, fibers,andfingerprintsusingtape lifttechniques.

adipocere Agrayishwaxlike substance that formsasaresultofaslowchemicalreactionbetweenbodyfat and water (hydrolysis) that occurs after death.The word adipocere comes from a combination ofthewords for fat (adipose tissue) andwax, and theconsistencyofadipocere is like soap.Thehydrolysisreactionthatproducesitisanexampleofsaponifica-tion, the chemical process by which fat is renderedinto hard soap. Adipocere formation can occur inbodies that are left in damp environments such asmud,wetsoil,swamps,orinwater.Theconsistencyof adipocere can result in the preservation of lines,shapes,andcontoursof thebody,and thedegreeofadipocereformationcanbeusefulforestimatingthepostmortem interval(pmi).Ifformed,itbecomesnoticeableabouteightweeksafterdeath,andthefor-mationprocessiscompletedbetween18monthsandtwoyears.

admissibility and admissibility hearing (Daubert hearing) Before any scientific evidence is presentedbeforeacourt,itmustbedeterminedtobeadmissible.Admissible evidencemust be reliable and relevant tothecaseathand,andforscientificanalysis,thecourt

must be assured that themethods used are scientifi-callyacceptableandreliable.Theintentofadmissibili-typroceedingsistopreventtheintroductionofresultsobtained by the use of poor science or pseudosci-enceortopreventtheadmissionofevidencethathasno bearing on the case. Admissibility hearings pro-videawayfornewscientifictestmethodstobeintro-ducedandacceptedasviabletoolsinforensicscience.Ifrequired, thesehearingsareheldseparatefromthecasepresentation.

The standards that courts use to determineadmissibility of evidence vary among the jurisdic-tions. Those following the Frye standard (Frye v. United States)requirethatnewmethodsbegenerallyacceptabletoasignificantproportionofthescientificdiscipline to which they belong. For example, newchemicaltestswouldhavetobegenerallyacceptedasreliableamongmostanalyticalchemists.Jurisdictionsthat follow the Federal Rules of Evidence and theDaubert v. Merrell Dow Pharmaceuticalsdecisionusemore flexible guidelines. Essentially, underDaubert,the trial judge is responsible for determining if thescientific evidence isusefulandrelevantand that theexpertpresenting it isqualified todiscuss the resultsandofferanopinion.The judgemustalsodetermineifthetestingmethodrestsonareliableandreasonablescientificfoundation.SuchhearingsarereferredtoasDauberthearings.

See also Daubert decision; frye decision.

adulterants Seecutting agents.

affidavit Written testimony taken from an individ-ualwhoisunderoathbeforeanauthorizedrepresen-tativeofacourt.Occasionally,forensicscientistsandother expertwitnesses offer testimony byway of anaffidavit.

affinity Seepartitioning and affinity.

age-at-death estimation When an unidentifiedbodyorcollectionofremainsarefound,acriticalstepintheidentificationprocessistodeterminetheapprox-imateageofthedeceased.Threecommonmethodsofdeterminingtheagearebasedonskeletaldevelopmentandmeasurements,dentaldevelopmentandcondition,and amino acid racemization (AAr), usually inteeth.Giventhatskeletalanddentalformationfollows

adipocere

aknownand consistent patternof development, esti-matesbasedonthesetechniquesarereliabletowithinayearforyoungerpeople.However,oncegrowthanddevelopmentarecomplete,estimatesbecomemoredif-ficultand,ingeneral,theolderthepersonis,thelarg-er the uncertainty in the age estimates. Specialists inforensicanthropologyworkwithbonesandskeletalmeasurements while forensic dentists (odontolo-gists)workwithdentalevidence,withsomeoverlapsoccurring.

Skeletal development and ossification (mineral-izationorhardening)followsaknownandconsistentpattern from early fetal stages until growth is com-pletedasanearlyadult.InformationcanbeobtainedfromX-raysanddirectmeasurements(anthropome-try)ofspecificbonesandbonestructuressuchastheknee,wrist,andfoot.Oncedevelopmentiscomplete,skeletal age determinations must rely on measure-ments taken, such as skull sutures and in the pubis(pelvic)area.Generally,onceapersonisintheirearly40s,degenerativechangesinbonesandjointswillbeevident, increasingwith age.However, other factorssuch as health, diet, occupation, and genetics com-plicate age estimates and drive uncertainties higher.From early fetal development until the mid-teens,dentaldevelopmentisanexcellentmethodofageesti-mation. Estimates are based on the known rates ofemergenceofbabyteethandtheirsubsequentlossasadult teeth replace them.Other developmentalmile-stonesareindicatedintheteethaswell.Forexample,the stresses of birth disrupt the normal metabolicprocesses,includingthoseinthecellsthatformteeth.Thisdisruptioncreatesalineinthedentincalledtheneonatallinethatiseasilydetectable.

Once the last permanent teeth are in place, ageestimationfromteethiscomplicatedbyfactorsinclud-ingdiet,dentalcareandhygiene,andgenetic factors.However, teethcanbeagedwithreasonableaccuracyusing amino acid racemization (AAR). This is a par-ticularadvantagesinceteetharedurableandcanwith-standenvironmentalextremes,includingseveretraumaandfire.

See alsoradiology, forensic.

Further ReadingSorg,M. H. Forensic Anthropology. In Forensic Science:

An Introduction to Scientific and Investigative Techniques.2ndedition.EditedbyS.H.JamesandJ.J.Nordby.BocaRaton,Fla.:CRCPress,2005.

airplane crashes Seetransportation disasters.

alchemy Anancientpracticethatcombinedscience,art,andelementsofmysticism.Mostancientculturesthat left records practiced alchemy, which grew outof mining, metallurgy, and medicine. The undercur-rent, even though the ancients did not recognize it,was chemistry. Alchemy was an odd and interestingblendofscience,art,andreligionthatfocusedontheconceptofpurificationandofseparatingmaterialthatwasconsideredpuresuchasgold,fromtheunpure,orwhateveritwasembeddedin.Thefirstmentionsofalchemydatetoaround400b.c.e.TheGreekshadaword chyma that described processes of metalwork-ing, and this might be one origin of the word, butthe Chinese and Egyptians recorded similar wordsalso related to metallurgy. All three cultures prac-ticed alchemy and the al part appears to have comefrom Arabic, forming al-chemy or the chemistry.Although analysis and transformation of gold andothermaterials was part of alchemy, from its incep-tion therewere strong religious, spiritual, andmysti-calbranchesandaspectstoit.Itwasonlyinthe16thand 17th centuries that themystical part supersededthepractical, correspondingwith theeventual riseofchemistryasascience.

Alchemists were technologists who learned byexperienceandpassedonwhattheylearnedtoaselectfew. It was not of particular interest to them whysomethingworked.Itdid,andthatwasgoodenough.Asaresult,innovationcameslowly.Fromtheforensicperspective,thekeycontributionoftheancientalche-mistswasintheirinterestinfireappliedtometallurgyandtheuseofheatasameansofseparatingmaterialsfromoneanother.Pyrochemistrywastoplayaroleinthefirstviabletestsforarsenic.Arabalchemistssuchas Jabir contributed many advances including theartofdistillationand the separationof alcohols.sir isaac Newton androbert Boyle were consideredto be among the last of the alchemists, living in the1600s, when chemistry was emerging from alchemyasaseparateandrecognizedscience.Afterthis time,alchemy drifted deeper into mysticism. However, itscontribution to chemistry and toxicology wasessentialtoforensicscience.

Further ReadingMoran,BruceT.Distilling Knowledge: Alchemy, Chemistry,

and the Scientific Revolution. NewHistories of Science,

alchemy

Technology, and Medicine. Cambridge, Mass.: HarvardUniversityPress,2005.

alcohol Ethyl alcohol (ethanol) is a central nervoussystem (CNS) depressant that is a factor in approxi-mately 40percent of fatal traffic accidents.Althoughalcoholsareaclassoforganiccompounds, theuseofthetermalcohol,particularlyinforensiccontexts,usu-allyreferstoethanol.Othercommonalcoholssuchasisopropyl(rubbingalcohol)andmethylalcohol(meth-anol or wood alcohol) are more toxic than ethanol,althoughlargedosesofethanolcanbefatal.Methanolisoccasionallyencounteredasapoisonfoundinhome-madeorbootlegliquorssuchasmoonshine.

Ethanol is a colorless volatile liquid that is com-pletely soluble in water. Because it is water soluble,ingestedethanolcanmovewithwaterinthebodyandthus quickly diffuses out of the stomach and uppersmall intestine (duodenum) into the bloodstream andultimately into the brain where intoxication effectsoccur. Approximately 20 percent of ingested ethanolis absorbed through the stomach wall and the restthrough the walls of the small intestine. Ethanol can

be removed from the body by metabolic processes(~90 percent) or by exhalation or in urine, perspira-tion,orsaliva(~10percent).Ethanolmetabolismtakesplaceintheliver,wheretheenzymesincludingalcoholdehydrogenase convert ethanol in a stepwise processto acetaldehyde, acetic acid, and to exhalable carbondioxide and water. Large quantities of acetaldehyde,alsoknownasethanal,areresponsibleformanyofthesymptomsofahangover.

Ethanol is a product of the yeast-driven fermenta-tionofsugarsandisfoundatpercentlevelsinbeer(45percentw/v[weighttovolume]),920percentinwines,and higher concentrations in hard liquors. In hardliquors,theethanolconcentrationisgivenastheproof,which is twice the percentage. Thus, liquor that is 50proofis25percentethanol(w/v).Althoughthenumberand types of drinks ingestedover a given time canbeusedtoestimatealcoholconcentrationsinthebloodandbrain,many factors determine how fast the alcohol isabsorbedandwhatdegreeofimpairmentresults.Thesefactorsincludethepresenceoffoodinthestomach,sexandweightoftheindividual,andrateofelimination.

Alcohol volatilizing from the blood and into the air in the lungs. This process is based on Henrys law (left), which applies to systems in which a material (here, ethanol) is distributed across the interface of a liquid (blood) and a gas (air). As ethanol leaves the blood in the lungs, it is exhaled and can be measured.

0 alcohol

Given these variables, the degree of impairmentmustbemeasuredbasedontheconcentrationofalco-holintheblood,andbyextensiontheconcentrationinthebrain,wheretheimpairmentoccurs.ThefirstlawsintheUnitedStatesaimedat intoxicateddriverswerepassed in 1938 in the states of Indiana and Maine.Since 1939, courts have accepted chemical tests forthe determination of blood alcohol concentra-tions (BAc). Field testsusedevices thatmeasure theconcentrationofalcoholintheexhaledbreath,andbyextensiontheconcentrationintheblood.Thesequan-tities can be related to each other based onHenrys law (illustrated in the figure on the previous page),whichstatesthatconcentrationofagasdissolvedinaliquid is proportional to the concentration of the gasabovetheliquid,assumingthetemperatureisconstant.Thisinterfaceofliquid(blood)togas(air)occursdeepin the lungs.Blood flowsadjacent to thewallsof thealveolarsacs,allowingcarbondioxideandethanoldis-solvedinthebloodtoescapeintotheairtobeexhaled.Oxygenisalsoexchangedatthisinterface.Forethanolinbloodincontactwithair,theHenryslawratiohasbeen determined to be approximately 2100:1, mean-ing that1milliliterofbloodwould contain the sameamountof ethanolas2100mLofair.Thus,bymea-suring the concentration of ethanol in the exhaledbreath, the BAC concentration can be estimated bycalculation.Earlystandardsforlegalintoxicationwere0.15 percent BAC, then decreased to 0.10 percent,andarecurrently0.08percentinmoststates.InmanyEuropeancountries,thelevelismuchlower,including0.02percentinSweden.BAClevelsabove0.35percentcan produce stupor and coma, and death can occurfrom respiratory suppressionatBACsof0.45percentandabove.

Dependingonthejurisdiction,abloodsamplemayalsoberequiredtodeterminetheexactBAC.Forensictoxicologists use gas chromatography (gc) or achemical test using alcohol dehydrogenase to experi-mentally determine the BAC from a blood sample.Collectionofthebloodsamplemustbedonecarefullyusingethanol-freedisinfectantsandtheproperproce-dures including a chain of custody, refrigeration,andtheadditionofanticoagulantsandpreservatives.

See alsoADme; breath alcohol; toxicology.

Further ReadingFenton,J.J.Chapter15,Alcohols.InToxicology: A Case

Oriented Approach.BocaRaton,Fla.:CRCPress,2002.

Kunsman, G. Human Performance Toxicology. InPrinci-ples of Forensic Toxicology.2nded.EditedbyB.Levine.Washington, D.C.: American Association of ClinicalChemistry,2003.

Levine,B.,andY.Kaplan.Alcohol.InPrinciples of Foren-sic Toxicology. Edited by B. Levine. Washington, D.C.:AmericanAssociationofClinicalChemistry,2003.

algor mortis Seebody temperature.

alkaline flame detector See nitrogen phospho-rus detector(NpD).

alkaloids A class of chemical compounds that areextractedorobtainedprimarilyfromseedplants.Theywerefirstisolatedinthe19thcenturyandwerecalledvegetable alkaloids. The pure compounds are usu-allycolorlessandbittertastingandareencounteredinforensic work as drugs or poisons. Alkaloids derivetheir name from the fact that they are basic or alka-line,andthisinlargemeasureaccountsfortheirbittertastes. In addition to carbon andhydrogen, alkaloidscontain nitrogen and usually oxygen. caffeine is atypicalalkaloid,containingbothnitrogenandoxygeninthemolecule.

There are three classes of alkaloids commonlyencounteredinforensicwork:

1. Opiate alkaloids: These are extracted from opiumpoppiesandincludeopium, morphine,andcodeine.

The molecular structure of caffeine, a typical alkaloid

alkaloids

These extracted alkaloids can be used tomake syn-theticorsemi-syntheticnarcoticssuchasheroin.

2. Xanthine alkaloids: This class includes familiarcompounds such as theophylline, theobromine,andcaffeine (previous page), which are found incoffee, tea, and chocolate. Although not illegal orcontrolled, they are encountered as ingredients inover-the-counter (OTC) pharmaceuticals and asdiluents(cutting agents)ofstreetdrugs.

3. Ergotalkaloids:Anergot isaseedlikepodproducedbyfungusthatcangrowoncerealcropssuchasrye.Manyof the ergot alkaloids are poisonousor hallu-cinogenic, including lysergic acid diethylamide(LsD).

cocaine is also an alkaloid and like most canexist in the freebaseor salt form.Cocaine freebase isa sticky, gummy substance prepared by extractingthe cocaine intoabasic solution.On theotherhand,cocaine hydrochloride (HCl) salt is a white powder.The freebase form ismorepotentand isused in free-basing,inwhichthedrugissmokedorinjected.

See alsodrug analysis; toxicology.

alternate light sources (ALS) Combinations oflights and filters used in forensic science tomakeevidencesuchaslatent fingerprints,biologicalflu-ids,andwritingondocumentseasiertosee.Thelightsource itself isusuallya strong lampsuchasaxenonarcorquartzhalogentypethatemitsanintensebeamof light that is channeled througha fiberoptic cable.This allows the analyst to focus the bright beam onasmallarea.With latent fingerprints, theanalystcanselectoneofmanychemicalsordyesthatwilladhereto the print and fluoresce after exposure to the lightsource.

See alsofluorescence.

Amelogenin gene Seesex determination.

American Academy of Forensic Sciences (AAFS)Thepreeminentnationalandinternationalforensicsci-enceprofessionalorganization,foundedin1948.Mem-bers, currently numbering about 5,000, are assignedto one of 10 sections, eachwith separate applicationrequirements: Anthropology, criminalistics, engineering,General,Jurisprudence,Odontology, pathology/Biology, psychiatry/BehaviorSciences,Questioned Documents, and toxicology. The

societys journal, Journal of Forensic Sciences, is theprimary, peer-reviewed publication in the field. TheacademyisheadquarteredinColoradoSpringsandhasanextensiveWebsiteatwww.aafs.org.

See alsoappendix i.

American Board of Criminalistics (ABC) Thisboard was formed in 1989 as a means to develop anational certification program for criminalists. Thehistory of the board traces back to the mid-1970swhen the Criminalistics Certification Study Com-mittee (CCSC, funded by a grant from theNationalInstitute of Justice, NIJ) looked at issues and prob-lemsassociatedwithawiderangingexaminationandcertification program. The California Associationof Criminalists (CAC) was the first to adopt a for-mal certification program based on a comprehensiveexamination administered to any criminalist seekingcertification.TheABCprogrambuilt upon theCACprocess and developed the ABC General KnowledgeExamination(GKE)aswellasspecialtyexaminationsin areas such as Fire Debris, Forensic Biology, andDrugIdentification.

See alsoappendix i.

American Board of Forensic Anthropology Seeappendix i.

American Board of Forensic Document Examin-ers Seeappendix i.

American Board of Forensic Entomologists (ABFE)Seeappendix i.

American Society for Testing Materials (ASTM)Anorganizationdevotedtothedevelopmentofvolun-tary standards and specifications fornumerousmate-rials, systems, services, and procedures. The ASTMwas founded in 1898 and now consists ofmore than32,000membersorganized into committees and sub-committees that develop detailed written documentsthatare sold toorganizations that request them.Sell-ingofthesewrittenprocedures(calledstandards)gen-erates most of the funding for this nonprofit group.Currently, thereare129 technical committees includ-ing Amusement Rides, Concrete and ConcreteAggregates, Glass, and Water. The Committeeon Forensic Sciences (E30) was formed in 1970 and

alternate light sources

has subcommittees dealing with criminalistics, questioned documents, pathologyandbiology, toxicology, engineering, odontology, jurispru-dence, physical anthropology, psychiatry andbehavioral science, interdisciplinary forensic sciencestandards, long-range planning, terminology, awards,andliaisons.Thescopeofthecommittee includesthedevelopmentof laboratorymethods,procedures,stan-dardreferencematerials,andstandardterminologyasitrelatestophysicalevidenceandforensicscience.TheorganizationmaintainsanextensiveWebsiteatwww.astm.org.

American Society of Crime Laboratory Direc-tors (ASCLD) An organization representing crimelaboratorydirectorsformedin1974toimprovecrimelaboratory operations and procedures. ASCLD coor-dinatesavoluntaryaccreditationprogramforforensiclaboratoriesthataddressesfacilities,management,per-sonnel,procedures,andsecurity,amongother things.Membershipisopentocurrentandformerlaboratorymanagersandforensicscienceeducators.

ASCLD/LAB is the ASCLD Laboratory Accred-itation Board that oversees the accreditation of fo-rensic laboratories. The board was formed in 1981and incorporated in 1988. Accreditation is grantedafter a laboratorymeets strict requirements on ana-lyst education and continuing education and train-ing, laboratory procedures and protocols, evidencehandling, quality assurance/quality control(QA/QC), and other aspects of laboratory opera-tion.Aspartofaccreditation,analystsparticipate inproficiency testing, and reaccredidation is requiredon a five-year cycle. In 2004, the accreditationguidelines were modified and now incorporate ele-mentsfromtheinternational Organization for standardization (isO). More than 250 laborato-ries are now accredited under the older legacy stan-dardsandthenewerisO-basedstandards.

amino acid racemization (AAR) Atechniqueusedin archaeology, geology, anthropology, andforensicsciencetodatematerialsandtodetermineage-at-death. Allamino acids except glycine can existintwoforms(enantiomers)indicatedbythenotationd- and l-. Biological processes, includingmetabolism,favor the l-formsofaminoacidsand soproteins thataremade in the body consist of l-amino acids.How-ever,ifatissueisshieldedfromthemetabolicprocess,

the amino acids will undergo a process of racemiza-tion inwhich some of the l-amino acidswill converttothed-formuntilaroughlyequalmixtureofd-andl-forms exist.Eachaminoacidhasadifferent rateofracemizationsothedegreeofracemizationfoundinatissuesamplecanbeusedtoestimatetheage.Therateofracemizationdependsprimarilyontemperatureandmoisture;thewarmerand/orthewettertheconditions,the faster theprocess.Thus, ifAAR is beingused toestimatetheageofadeceasedperson,theenvironmen-talconditionsinwhichasampleorbodyisfoundareimportant.

Techniques for AAR were first demonstratedin 1968 using the amino acid isoleucine. Analyticalmethods vary, but a common procedure is to isolatethe amino acid of interest from a sample using ion chromatography (ic), and then determine of theratioofd-and l-formsusinggas chromatography(gc)orhigh performance liquid chromatogra-phy(HpLc).Generally,onlyasmallsampleisneeded.AAR has been applied to tissues including the discsbetweenvertebrae,thelensoftheeye,andpartsofthebrain,butforensicapplicationsfocusontheanalysisoftheasparticacidinteeth.

Once a tooth is fully developed, the dentin por-tionissurroundedbyenamelandiseffectivelyisolatedfrom metabolic processes. This is not true of bone,which is continually in contactwith blood andotherbodyfluids.Thus,aminoacidspresentintheproteinsinthedentinwillundergoracemizationevenwhilethepersonisalive.Sincebodytemperatureisstable,asaremoisture levels, the rateof racemization is fairly con-stantandtheratioofd-asparticacidtol-asparticacidcanprovideareasonableestimateofage(withinafewyears)evenwhenothertechniquesfail.Althoughrace-mizationcontinuesafterdeath,therateslowsasbodytemperaturedrops.

See alsoodontology.

Further ReadingMeyer,V.R. AminoAcidRacemization:ATool for Fossil

Dating.Chemtech(July1992):412.Ohtani, S., and K. Yamamoto. Age Estimation Using the

RacemizationofAminoAcidinHumanDentin.Journal of Forensic Sciences36,no.12(1991):792.

amino acids Themolecularbuildingblocksofpro-teins. As the name indicates, all of these moleculeshaveat leastoneacidicsite (functionalgroup)aswell

amino acids

asanNH3(aminoasinammonia)group.Thefigureofagenericaminoacid(below)showsthethreecom-monmethodsinwhichthesemoleculesaredrawn.ThetermR indicatesdifferentgroupsthatvarydependingonwhich amino acid it is. The carbon that is at thecenteroftheaminoacidiscalledthealpha()carbon,and groups that are attached directly to this carbonarecalledgroups.Abeta()groupwouldbelocatedtwocarbonsawayfromthecentralcarbon.Forclarity,hydrogenatomsorCH3groupsareusuallynotlabeled.

Proteins are polymers of amino acids, meaningthat they are built by linking many (poly) aminoacids together in a long chain. Twenty amino acidsmake up the structure of proteins: alanine, arginine,asparagines,aparaticacid,cysteine,glutamine,glutam-ic acid, glycine, histidine, isoleucine, leucine, lysine,methionine, phenylalanine, proline, serine, threonine,tryptophan, tyrosine, and valine. Each amino acid isdistinguishedfromtheothersbyadifferentRgroupasshowninthegenericaminoacidstructure.

All amino acids except glycine can exist in twoforms called stereoisomers. In stereoisomers, thesame functionalgroupscanbeattached to thecentralcarbon in the same way to create molecules that aremirror imagesof eachother.Asan example, considerthe handsboth are the same structure that differonly in the way in which the fingers and thumb arearranged.Therighthand isa stereoisomerof the left.Stereoisomersinteractwithpolarized lightindiffer-entways,leadingtothetermoptical isomersorenan-

tiomers.Isomersarenamedbasedonthedirectioninwhich they rotateplanepolarized light, to the left(levorotatory or -) or to the right (dextrorotatory or+).Thus, the twooptical isomersofalaninewouldbenamedd-alanine(or+alanine)orl-alanine(oralanine)asshown.Noticethattheonlydifferenceistheorienta-tion of the amino group around the-carbon,whichis called a chiral center. A mixture containing equalamountsofthedandlentantiomersiscalledaracemicmixture,andtheprocessbywhichoneenantiomercon-vertstoanotheriscalledracemization.Naturetendstofavor the l-forms of amino acidswhilemost chemicalsynthesesproduceamixtureofthed-andl-forms.

amitriptyline Seeelavil.

ammunition For modern firearms, ammunitionconsists of a projectile (bullet or pellets) and acar-tridge case containingpropellant and theprimerthatignitesit.Asingleunitisreferredtoasaroundof ammunitionandall partsof a roundhave value asphysical evidence. The figures on the next page showthemostcommontypesofammunitionencounteredinforensicscience.

Thefunctionofammunitionistoexploitthechemi-calenergystoredinthepropellant(gunpowder)byignit-ingit.Theburningreleasesheatandrapidlyexpandinggases that are trapped behind the projectile in thebreechandbarreloftheweapon.Whensufficientpres-sure is built up, the pressure accelerates the projectileforward,givingitkineticenergy(theenergyofmotion)that isproportional to theweightof theprojectileandthe speed towhich it is accelerated.Theequation thatdescribesthisrelationshipis:KE=mv2.Uponimpact,thekineticenergyoftheprojectile istransferredtothetargetthatitstrikes.Cartridgeammunitionisdesignedtobeself-containedsothatallthatisneededisasimplemechanicalmethod(linkedtothetrigger)thatcanstriketheprimerandignitethepropellant.

The inventionofgunpowder (blackpowder)hasbeenattributedtomanyculturesincludingtheGreeksandtheChinese.Blackpowdercontainscharcoal(car-bon)atabout15percentbyweight,potassiumnitrate(KNO3 or saltpeter) at 75 percent, and sulfur at 10percent.Although used for centuries on a battlefield,the copious smoke produced by burning gunpowdereitherquicklyobscuredthevieworgaveawaytheposi-tionof those firing.Smokelesspowderwasdevelopedforuseby theFrencharmy in1876andhas replaced

Amino acids, a class of molecules defined by an acidic portion (COOH structure) and an amino (NH) site. In this generic amino acid structure, the R represents different chemical structures.

amitriptyline

black powder in commercial ammunition, althoughit is still used by collectors and hobbyists. Smokelesspowdercontainscellulosenitrateandorganicstabiliz-ersandismanufacturedtocarefullycontrolthesizeofthegrains.Powderdoesnotexplodewhenignited(itisconsidereda lowexplosive); rather, itburnsveryrap-idly,andsinceburningusuallyoccursatthesurfaceofparticles,thesizeofthoseparticlesdictateshowmuchsurfaceareaisavailableandhowfasttheburningwilloccur.The termgunpowder nowcommonly refers tosmokeless powder even though historically the termhasbeenappliedtobothsmokelessandblackpowders.

Thefunctionoftheprimeristoignitethepowder.Theprimer consistsof a shock-sensitivematerial thatexplodes when struck by the firing pin. Flash holesdirect the explosion to the propellant where ignitionoccurs.Olderammunitionandsmallercaliberammu-nitionusearimfirecartridgeinwhichtheprimerrunsaround the circumferenceof the rimwhileother rifleand pistol ammunition use centerfire cartridges. Thecartridge case itself is usuallymade of brass and theterm brass often is used to refer to empty cartridgecasingsregardlessofwhattheyaremadeof.Brasscas-ingscanbereloadedandreused,butcasingsmadeoutofsoftermaterialssuchasaluminumare intendedforsingleuse.

Bullets vary in composition, coating (jacketing),and shape.Wad cutters, used for target practice, areblunt-nosed lead slugs that are not normally usedoutside of a shooting range. Bulletsmay also have aroundedorpointedshapeasiscommoninrifleammu-nition.Bulletsaremadeofleadorleadalloysandmaybe jacketed or semi-jacketed tominimize the transferoftherelativelysoft leadtothelands and groovesinsideof the gunbarrel. Jacketing is usuallymadeofcopper, copper alloys, or aluminum, all ofwhich areharderthanlead.Manyothervariationsexistsuchashollow point ammunition and Teflon-coated bullets.The latter are a law enforcement concern given theirability topenetratebodyarmor.Thecaliberofagun(rifle andpistol) is ameasurementof thediameter ofthe gun barrel, so the ammunitionmustmatch thesedimensions. Caliber is given in bothmetric units (9-millimeter) and hundredths of an inch (0.38), withsome variants. For example, rifle ammunition that is

Schematics of handgun and rifle ammunition showing the locations of the primer, propellant, and bullet (not to scale)

Cutaway view of shotgun ammunition

ammunition

labeled as .30-06 (thirty-ought-six) means thatthebulletisfora.30caliberrifleandthattheammu-nitiontypewasintroducedin1906.

shotgunammunitiondiffersinseveralwaysfromrifle and pistol cartridges.The cartridge case ismadeofplasticorcardboardandiscrimp-sealedatthetop.Theprojectilesaresmallleadorsteelpellets,thesizeofwhich reflects the gauge of theweapon.Originally,thegaugeofapelletreferredtohowmanypelletsofagivensize(thesameasthebarreldiameter)wereneededto reach aweight of one pound. Twelve-gauge pelletswerethosethateachweighedapproximately1/12ofapound(.45kg)andwouldfitinthebarrelofa12-gaugeshotgun.Nowthetermgaugeissimilartocaliberanddescribes the sizeof the shotgunbarrel.Highergaugenumbersmeansmallerbarrels, soa12-gauge shotgunhas a larger diameter barrel than a 16-gauge, just as12-gaugeshotislargerthan16-gaugeshot.

The pellets are separated from the propellant bywadding that can be made of paper or plastic. Thiswadding material can provide important evidencerelatingtothemanufactureroftheammunitionanditsgauge.

See alsofirearms; gunshot residue (gsr).

amphetamines Stimulants (amphetamine,dextroam-phetamine,andmethamphetamine)thatwereoncefree-lyprescribedforweightcontrol,fatigue,andnarcolepsy(sleeping sickness).Bothamphetamineandmetham-phetaminewereusedduringWorldWar IIasa stimu-lant for troops, and after the war they were used bytruckers,dieters,andathletes.Asabusespread,thefed-eral government limited the amount of amphetaminesthat could bemanufactured and removedmany typesfromthemarket.Asaresult,illegaldemandisnowsup-plied primarily by clandestine laboratories pro-ducing methamphetamine. Street names for the drugsinclude speed, ice, crystal, andBennies, dependingonidentity and form. Data provided by the 20022005NationalSurveyonDrugUseandHealthindicatedthatapproximately12millionAmericanshadtriedmetham-phetamineduringtheirlifetime.Forhighschoolseniors,the2005 Monitoring the Future survey indicated that2.9percenthadusedthedrugbythe12thgrade.

Amphetamines are psychologically addictive, butdebate continues as to the degree of physiologicaldependencetheyproduce.Amphetaminesstimulatethesympatheticnervoussystem,whichcontrolsheartrate,blood pressure, and respiration, and excessive use can

leadtosevereeffectssuchashallucinations,convulsions,prickling of the skin, unpredictable emotional swings,extreme aggression, and death. Amphetamines can betakenorally,snorted,injected,orsmoked.Adangerousformofmethamphetamine,knownasice,ismadebyslow evaporation and recrystallizationofmethamphet-amine as a hydrochloride salt, which results in large,clearcrystalsthatcanbesmoked.Iceisconsideredtobebothtoxicandaddictive.Otherformsofamphetaminesinclude pills (white crosses or Bennies), liquids,andpowders.Occasionally, substances sold illegallyasamphetaminesareanalyzedandfoundtocontainnoth-ingmorethansugarandcaffeineorephedrine.

All amphetamines are synthetic and are based onaphenylethylamine(orphenethylamine)skeleton.Theyare defined as Controlled Substances and are listedon Schedule II of thecontrolled substances Act(csA). In addition to the three amphetamines alreadymentioned, this class of drugs also includes MDMA(Ecstasy), phenmetrazine (Preludin), phendimetrazine,MMDA (5-methoxy-3,4-methylenedioxyamphetamine),STP (4-methyl-2,5-dimethoxyamphetamine), andmes-caline (3,4,5-trimethoxyphenylethylamine). Many oftheserelateddrugssuchasmescalinearehallucinogens.

As synthetics, amphetamines can be made start-ingwithprecursorchemicals.Anoldermethodusedphenyl-2-propanone (P2P) as the starting point,

Amphetamine and the related compound methamphetamine, both based on a phenethylamine skeleton

amphetamines

but inclusionof thismaterialon the listofcontrolledsubstances reduced its availability and forced clan-destine labs to switch to other synthetic routes. Thecurrently favored route starts with ephedrine, aningredient in over-the-counter (OTC) antihistamineandcoldmedicines.Otheringredientsinthissyntheticroute can include ammonia, sodium hydroxide (lye),andredphosphorus.

Forensic analysis of suspected amphetaminesbeginswithsimplechemicalcolortests(presumptive tests)thatindicatethepossiblepresenceofthecom-pounds.Theanalysisprogressesthroughmorespecifictestsincludingcrystal tests, thin layer chroma-tography (tLc), and instrumental techniques suchas infrared spectroscopy (ir) andgas chroma-tography/mass spectrometry (gc/ms). Forensicchemistsalsohelpidentifythesynthesismethodbasedon other materials present in the sample. In mostcases, it is possible to determine the material withwhichthematerialisdiluted,materialsknownascut-ting agents.

Seealsoprofiling.

Further ReadingMoore, K. Amphetamines/Sympathomimetic Amines. In

Forensic Toxicology. 2nd edition. Edited by B. Levine.Washington, D.C.: American Association of ClinicalChemistry,2003.

amplified fragment length polymorphism (AFLP)SeeDNA typing.

anabolic steroids A class of synthetic steroidsrelated to themale sex hormone testosterone.Wide-spread abuse of these drugs by athletes, despite thepotentialforseverelong-termsideeffects, ledtoana-bolic steroids being declared Controlled Substancesin1991.Theyare listedonSchedule IIIof thecon-trolled substances Act (csA), along with drugssuch as barbiturates and some codeine prepara-tions.Steroidsareconsidered tobe illegal substancesby most amateur and professional athletic organiza-tions including the InternationalOlympicCommittee(IOC).AlthoughonceviewedasprimarilyaprobleminprofessionalathleticandOlympic-levelcompetition,recent surveys indicate that a growing percentage ofhighschoolathletes,bothmaleandfemale,havetriedor use steroids. According to the 2005 Monitoringthe Future Survey, 2.6 percent ofmale high schoolseniorshadusedanabolicsteriods,ashad0.4percentoffemales.

As a biochemical class, steroids are lipids (fats)thatarenothydrolyzable(donotreactwithwater).Allsteroidsarebuiltonasteroidnucleusoffourringsof carbonatoms, threeofwhich contain six carbonsandonethatcontainsfivecarbons.Commonsteroidsincludecholesterolandsexhormones including thoseused inbirthcontrolpills.Anabolic steroidsare syn-theticsteroidsrelatedtotestosterone,amalesexhor-mone that promotes the development of secondarymale characteristics (called androgen effects) such asdeepening of the voice. Testosterone also acceleratesmusclegrowthandpromotesrapidhealingof injuredmuscles; these and related effects are called anaboliceffects. Synthetic anabolic steroids are designed tominimize the androgen effects, but these cannot becompletely eliminated. In athletics, anabolic steroidsare used as performance-enhancing drugs that pro-mote development of muscular strength and bulk,reduce recovery time, and allow training at a higherlevel than otherwise possible. Dangers of anabolicsteroidmisuse includekidneyand liverdamage, livercancer, masculinization and infertility in women,impotenceinmen,andunpredictableemotionaleffectsincludingmoodswingsandextremeaggression.Someoftheseeffectsareirreversible.Steroiduseisparticu-larly dangerous for adolescents, for whom they caninterferewithbonegrowth.

Chemical precursors to methamphetamine

anabolic steroids

Anabolic steroids and their metabolic productsare detected in blood and urine using gas chro-matography/mass spectrometry (gc/ms) andother toxicological techniques. Masking agentsare sometimes used to disguise steroid use, but evenif the steroids and their metabolites are not detect-able,themaskingagentsusuallyare.Afamousrecentcaseoccurred at theOlympicGames in1988,whereCanadian Ben Johnson won the 100-meter dash inrecord-settingtime,onlytohavehisgoldmedaltakenawaytwodayslaterwhenhisurinetestedpositiveforstanozolol,ananabolicsteroid.Hewassuspendedandlaterreturnedtocompetitivetrack,onlytobeperma-nently banned in 1993when he was again found tohavebeenusinganabolicsteroids.Morerecently,pro-fessionalbaseball has adopted stricter rules and test-ingtoaddresssteroiduse.

See alsoDrugTestinginSportsessay,p.116.

analgesics A class of drugs that relieves or reducespainbydepressing the centralnervous system (CNS).Aspirin and acetaminophen (Tylenol) are commonover-the-counter (OTC) analgesics. Many narcoticdrugs, including opiate alkaloids, such asmorphineandcodeine,arepowerfulanalgesics,andabusecanleadtophysiologicalandpsychologicaldependence.

See alsodrug analysis.

analogs Seedesigner drugs.

analysis, comparison, evaluation, and verificationSeeAce-v.

analytical chemistry Seechemistry, forensic.

analytical power Atermusedtoexpresstheabilityofachemicalanalysistoidentifyatargetcompoundor

Example structures of different steroids, all based on the same steroid nucleus

analgesics

othersubstancedefinitively.Analyticalpowercanrefertoa single testora seriesof testsdesigned tonarrowdown the possible identification of an unknown sub-stance.Forexample,inforensicdrug analysis,acom-mon form of evidence is an unknown white powder.Theanalystcanapplyaseriesofsimplepresumptive teststohelpnarrowdownthepossibleidentificationsof the powder. Using a series of tests provides moreanalytical power than a single test becausewith eachtest,thenumberofpossibilitiesdecreases.

Anastasia and the Romanovs At aroundmidnighton July 16, 1918, CzarNicholas II of Russia and hisfamilywerebrutallyexecutedbyBolshevikrevolutionar-iesledbyVladimirLenin.ThekillingstookplaceinthebasementofamansioninYekaterinburginSiberiaandwere carriedoutby severalmenusingguns,bayonets,and clubs. Eleven purportedly died that night, includ-ingtheczar;hiswife,CzarinaAlexandra;theirsonandheir,Alexei;theirfourdaughters,Olga,Tatiana,Marie,andAnastasia;thefamilyphysician;amaid;acook;andafootman.Interestinthecasewasfueledovertheyearsby rumors that the youngest daughter, Anastasia, hadsomehowsurvivedandescapedtotheWest.OneofthemostinsistentAnastasiaclaimantswasawomannamedAnnaAnderson,whodiedintheUnitedStatesin1984.Intheearly1990s,popularattentionagainfocusedonthe mystery when the Russian government (no longercontrolledbythecommunists)excavatedapitnearthetownthathadlongbeenrumoredtobethegraveoftheRomanovsandtheirattendants.Portionsofnineskele-tons,badlydamagedbyblows,explosives,burning,andacid,wererecovered.Usingskeletalmeasurements,den-tal records, and computer facial projection techniques,theRussianstentatively identifiedthemasthe imperialfamily,butwithtwomissing.

In 1992, a team from the United States, led bythe eminent forensic anthropologist William Maples,arrived inRussia toassistwith the identification.Theteamwasable to identify thenineandconcludedthatthe two missing skeletons were those of Alexei andAnastasia. This finding fanned survival rumors, atleast forAnastasia.Alexeiwasahemophiliacandfewbelieved he could have survived the savage attacks oftheexecutioners.Basedoninterviewswithparticipantsintheexecutionandtheaftermath,theconsensusoftheteamwasthatbothhaddiedbutthatthebodieswereburnedatalocationnearthepitwherethenineotherswereburied.Thesiteoftheburningwasnotlocated.

Further confirmation came in 1993 when PeterGillandKevinSullivanof theBritishForensicSciencesServiceslaboratoryconductedDNAanalysis.Preliminaryworkprovedthatfiveofthevictimswerefromthesamefamily but could not positively identify them as partof theRomanov family.Thiswasachievedusingmito-chondrial DNA (mtDNA), which unlike the DNA inthenucleusofthecellispasseddirectlyandunchangedfrom mother to child. Analysis of the mitochondrialDNAwasperformedusingsamplesfromthepitaswellasthosefromtheczarsbrother(whodiedin1899)andBritainsPrincePhillip.Theczarina, likePrincePhillip,wasadescendantofQueenVictoria,whichprovidedtheinvestigators with samples of known maternal lineageforcomparison.Theresultsshowedthatthefivefamilymembersrecoveredfromtheburialpitwerealmostcer-tainlytheremainsoftheRomanovs.Theofficialdebateendedin1998,whentheroyalfamilyandtheirservantswerelaidtorestafterafuneralinSt.Petersburg.

Anna Anderson, the woman who claimed to beAnastasia, died a decade before the tests were per-formedandherbodywascremated.However,shedidhave an operation before her death, and the hospitalhad retained a portion of her tissue. DNA analysisproved that she was not related to the Romanovs.While Anastasias fate cannot be known for certain,thelikelihoodisthatshediedwithherfamily.

Further ReadingGlausiusz,J.RoyalD-Loops.Discover,January1994,90.Maples,W.,andM.Browning.TheTsarofAlltheRussias.

InDead Men Do Tell Tales.NewYork:Doubleday,1994.Quinn-Judge, P. Final Rites for the Czar.Time, July 27,

1998,34.

animal hairs and fibers Seefibers; hairs.

anisotropy Anopticalpropertyofsomecrystalsandfibers useful in the forensic analysis of evidence suchasdust,soil,andfibers.Amaterialthatisisotropicforagivenopticalcharacteristicwillhavethesamevalueof that characteristic regardless of the direction fromwhich the light is coming. In contrast, anisotropicmaterialshaveanonuniformdistributionofsuchchar-acteristics. Solidmaterials that aremade up ofmole-cules that are randomly placed ormolecules that arenotsymmetricwillbeisotropic.Anexampleofaniso-tropicmaterialistablesalt,whichismadeupofsimplecubic(symmetrical)crystalsofsodium(Na+)andchlo-ride(Cl-).Manytypesofglassarealsoisotropic.Other

anisotropy

kindsofcrystalsandmanypolymers(whichconsistoforderedsubunitsbondedtogether)areanisotropic.Theterm birefringence is also used to describe a formof anisotropy. Birefringence of polymers is importantforensicallysincemanyfiberssuchasnylonandLycraconsistof syntheticpolymers.Birefringence is studiedusingapolarizing light microscope(pLm).

See alsodust analysis; microscopy.

Further ReadingDe Forest, P. R. Foundations of ForensicMicroscopy. In

Forensic Science Handbook. Vol. 1. 2d ed. Edited byR.Saferstein.UpperSaddleRiver,N.J.:PrenticeHall,2002.

Nomenclature Staff, Royal Microscopy Society. RMS Dic-tionary of Light Microscopy.RoyalMicroscopySocietyMicroscopy Handbook #15. Oxford: Oxford UniversityPress,1989.

anthrax A deadly bacteria that was sent throughtheU.S.mail duringOctober andNovemberof2001.Five people were killed, 13 sickened, and hundredsmoreexposedandtreated.NexttotheinvestigationoftheSeptember11,2001,attacks, the investigation intothis crimewas the largest undertaken by the FBI andcrossed many traditional jurisdictional lines. Forensicscientists as well as many other scientists from manyagencies including the U.S. Army, the EnvironmentalProtection Agency (EPA), and the Centers for DiseaseControl (CDC) were involved. The bacteria Bacillus anthracis, which is foundmostly in domesticated ani-mals such as sheep and cattle, cause the anthrax dis-ease. The spores of the bacteria can lay dormant insoil for years and infect humans; the spores can alsobe manipulated to form a potent biological weapon.Thereare three typesof infection thatpeople canget.First is cutaneousanthrax,whichariseswhenbacteriaget into the skin throughacutor similarwound.Theskinblackensanddies,althoughinfectedpeoplerarelydieiftheyobtainpromptantibiotictreatments.Inhala-tionanthraxismuchmoredeadly.Theearlysymptomsaresimilartoacoldorthefluandbythetimemedicalpersonnelrecognizethedanger,itisusuallytoolatetopreventdeath.However, ifantibiotic therapy isstartedsoonafterexposure,chancesofsurvivalaremuchgreat-er.Thethirdformofanthraxisintestinal,alsodeadlyifnottreatedearly.Testsforanthraxincludestainingandmicroscopic study of the bacteria and spores throughsophisticatedgeneticanalysistodeterminethestrain.

See alsoLearningfromTragedy:ForensicScienceandTerroristAttacksessay,p.128.

Further ReadingCenters for Disease Control (CDC). Anthrax. Avail-

able online. URL: www.cdc.gov/ncidod/dbmd/diseaseinfo/anthrax_g.htm.DownloadedFebruary29,2008.

Anthropological Research Facility (ARF) Locatedat theUniversityofTennesseeatKnoxville, this facil-ityusesdonatedhumanremainsandanimalcarcassestostudytheprocessofdecomposition.Amaingoalofthe research is to improve estimatesof thepostmor-tem interval(PMI,time-since-death)andtoprovideaworkinglaboratoryforforensicanthropologists.Dr.William M. Bass founded the facility in 1972. ThefacilityissometimesreferredtoastheBodyFarm.

See also anthropology, forensic; ForensicScienceinLiteratureessay.

Further ReadingBass,Bill, and Jon Jefferson.Deaths Acre.NewYork: Pen-

guin,2004.

anthropology, forensic The analysis and study ofskeletalremainsthatare involved in legalprocedures.Anthropology is a wide-ranging field that studiesmany aspects of human culture and biology from itsearliest roots. The discipline can be divided into cul-tural anthropology and physical anthropology, thebranchthatexamines,amongotherthings,osteology.Osteologyisthestudyofthevariability,development,growth,andevolutionofthehumanskeleton,anditisfrom osteology, as well as archaeology and medi-cine,thatforensicanthropologyhasemerged.Physicalanthropologists have been assisting law enforcementsince the earlypartof the last century,but the emer-gence of forensic anthropology as a distinct forensicdisciplinedidnotoccuruntillater.Oneofthepivotalsteps was the founding of the Central IdentificationLaboratory(CIL)bytheU.S.Armyin1947.Thelabo-ratory,locatedatHickmanAirForceBaseinHawaii,grew out of work done by physical anthropologistsduringWorldWarII,wheretheyassistedthearmyinidentificationandrepatriationofremains.Inaddition,theSmithsonianhasalonghistoryofassistingtheFBIwithforensicanthropologyquestions.Itwasnotuntilthe 1970s that the term forensic anthropology waswidely used and accepted. In 1972, the American Academy of forensic sciences (AAfs) added aforensicanthropologysectionandin1977,theAmeri-can Board of Forensic Anthropology (ABFA), which

0 anthrax

regulatespracticesandprovidescertificationforprac-titioners,wasformed.

Whenstudyingevidence, the forensicanthropolo-gistmustfirstdetermineifamaterialreallyisboneorteethandifso,whetheritishuman.Itisalsoimpor-tanttodeterminetherelativeageoftheboneasancient(generallyolderthan500years),historic(50050yearsold),orcontemporary;however,thesetimeframesvarywithcontext.Oncethesefactorshavebeenestablished,the remains can be used to determine identification,ageatdeath,sex,race,timesincedeath(postmortem interval [PMI]), stature, and manner and circum-stances of death. Successful identification of skeletalremainsdependsonmanyfactorssuchaswhatportionoftheskeletonisfound,itscondition,stateofdecom-position,presenceofpersonal items (suchas jewelry),and the extent of records antemortem keptwhen thepersonwas living. Identification tasks can be greatlycomplicatedinthecaseofmassdisasters(commingledremains), fire and cremation (cremains), and scav-engeractivityandassociatedscatteringofbones.Thecommon techniques used in identification include theuseofdental records (odontology),facial recon-struction, and analysis of mitochondrial DNA.Determining the manner and circumstances of deathinvolves looking for evidenceof diseases anddamagesuch as bone injury caused by stabbing or firearms.Chemical analysis of the bones can sometimes revealthepresenceofpoisonssuchasarsenic.

See also age determination; archaeol-