Criminal Investigative Criminal Investigative TechniquesTechniques

Criminal ProfilingCriminal Profiling

““Profiling is neither a readily Profiling is neither a readily identifiable nor a homogenous identifiable nor a homogenous entity and its status is entity and its status is properly regarded as a properly regarded as a professional sideline not professional sideline not amounting to a true science” amounting to a true science” (Gudjonsson & Copson, 1997).(Gudjonsson & Copson, 1997).

Is Criminal Profiling for Real?Is Criminal Profiling for Real? Most criminal profilers are FBI Most criminal profilers are FBI agents, not psychologistsagents, not psychologists

Number of criminal profiling jobs in Number of criminal profiling jobs in the country is extremely small the country is extremely small (fewer than 26).(fewer than 26).

Few psychologist receive training in Few psychologist receive training in profiling, no graduate programs profiling, no graduate programs offer this trainingoffer this training

Current needs for ProfilingCurrent needs for Profiling Not appropriate for every crimeNot appropriate for every crime

Most appropriate for serial crimesMost appropriate for serial crimes• ArsonistsArsonists• Serial bombersSerial bombers

Three approaches to profilingThree approaches to profiling• HistoricalHistorical• Common characteristicsCommon characteristics• Crime scene characteristicsCrime scene characteristics

Three approaches to profilingThree approaches to profiling HistoricalHistorical

• Review of historical dataReview of historical data

Common characteristicsCommon characteristics• Constructing a descriptive profile of a Constructing a descriptive profile of a crime classificationcrime classification

Crime scene characteristicsCrime scene characteristics• Modus operandiModus operandi• Criminal’s signatureCriminal’s signature

Current Approaches to ProfilingCurrent Approaches to Profiling

Crime scene analysisCrime scene analysis

Criminal-profile generating processCriminal-profile generating process• Study of the nature of the crimeStudy of the nature of the crime• Analysis of the crime sceneAnalysis of the crime scene• Examination of background and Examination of background and activities of victimsactivities of victims

• Possible motivating factorsPossible motivating factors• Description of the perpetrator Description of the perpetrator

Crime Scene AnalysisCrime Scene Analysis

Crime scene Crime scene analysis is used analysis is used by criminal by criminal profilers to profilers to develop an develop an offender offender description.description.

Evaluation of ProfilingEvaluation of Profiling

EffectivenessEffectivenessMay lock in to wrong profilesMay lock in to wrong profiles• 2.7% lead to identification of the 2.7% lead to identification of the offenderoffender

• Poor research, small number of Poor research, small number of participants, small experimental participants, small experimental effectseffects

The Polygraph TechniqueThe Polygraph Technique The Lie DetectorThe Lie Detector

Uses for the polygraphUses for the polygraph

• Assess honesty of exculpatory Assess honesty of exculpatory statements given by subjectsstatements given by subjects

• Review status of employees whose work Review status of employees whose work involves security mattersinvolves security matters

• Assess behavior of probationers (sex Assess behavior of probationers (sex offenders)offenders)

• Child custody casesChild custody cases• appeals appeals

Criticisms of Polygraph ProceduresCriticisms of Polygraph Procedures

British Psychological SocietyBritish Psychological Society • Use of nonstandardized proceduresUse of nonstandardized procedures• Mislead subjects about test’s Mislead subjects about test’s accuracyaccuracy

• Create anxiety in subjects to Create anxiety in subjects to encourage confessionsencourage confessions

• Violate subject’s privacyViolate subject’s privacy

The Procedures involved in The Procedures involved in Polygraph TestingPolygraph Testing

Electrodes are used to record Electrodes are used to record physiological changes during an physiological changes during an interviewinterview

Measures such as heart rate, Measures such as heart rate, respiration rate, blood pressure, respiration rate, blood pressure, and galvanic skin responseand galvanic skin response

Measures are recorded on graph paper Measures are recorded on graph paper or displayed digitally on a computer or displayed digitally on a computer screen and stored electronically screen and stored electronically

Sources of Inaccuracy in TestingSources of Inaccuracy in Testing

Two potential sources of Two potential sources of inaccuracyinaccuracy

• Physiological measures do not Physiological measures do not directly measure dishonesty; directly measure dishonesty; rather need to infer lying from rather need to infer lying from emotional reactivityemotional reactivity

• Difficulty of accurately measuring Difficulty of accurately measuring physiological activity and physiological activity and quantifying these measures into quantifying these measures into ‘truth’ or ‘deceptive’ responses‘truth’ or ‘deceptive’ responses

Quantifying Physiological Quantifying Physiological ResponsesResponses

Use subjective judgments regarding Use subjective judgments regarding differences in emotional reactivity differences in emotional reactivity to questions - can be minimized by to questions - can be minimized by using computer programsusing computer programs

Difference score between reactions Difference score between reactions to the two types of questionsto the two types of questions

Difference scores introduce Difference scores introduce additional error because the additional error because the obtained score is less reliable than obtained score is less reliable than the scores it is based on due to the the scores it is based on due to the additional error introduced from additional error introduced from each separate scoreeach separate score

Techniques used in TestingTechniques used in Testing

The Control Question Technique The Control Question Technique (CQT)(CQT)

• Consists of approximately 10 Consists of approximately 10 questionsquestions

• Relevant questions deal with the Relevant questions deal with the question at hand (crime, security, question at hand (crime, security, etc) and control questions deal etc) and control questions deal with possible past behaviors that with possible past behaviors that may elicit emotional reactivitymay elicit emotional reactivity

Control Questions TechniqueControl Questions Technique• Assumption is that relevant questions Assumption is that relevant questions will generate more emotional reactivity will generate more emotional reactivity than control questionsthan control questions

• Control questions measure the person’s Control questions measure the person’s level of reactivitylevel of reactivity

• Control questions must elicit lying, Control questions must elicit lying, must be chosen carefullymust be chosen carefully

• Innocent will respond to both control Innocent will respond to both control and relevant questions with equal and relevant questions with equal emotional reactivityemotional reactivity

• Guilty person will show more reactivity Guilty person will show more reactivity to relevant questions than control to relevant questions than control questions.. Creating a difference scorequestions.. Creating a difference score

The Relevant-Irrelevant TestThe Relevant-Irrelevant Test

First most widely used procedureFirst most widely used procedure Mostly discarded by examiners due to Mostly discarded by examiners due to false positivesfalse positives

Relevant questions deal with issue Relevant questions deal with issue at hand (crime, security, etc.)at hand (crime, security, etc.)

Irrelevant question is innocuousIrrelevant question is innocuous

The Relevant-Irrelevant TestThe Relevant-Irrelevant Test AssumptionsAssumptions

• Relevant questions will elicit Relevant questions will elicit emotional reactivity in guilty emotional reactivity in guilty individuals and not in innocent individuals and not in innocent peoplepeople

• Irrelevant question will not Irrelevant question will not elicit emotional reactivityelicit emotional reactivity

• Problem: relevant question can Problem: relevant question can elicit emotional reactivity in elicit emotional reactivity in innocent peopleinnocent people

A Third ApproachA Third Approach Use of questions related to the crime that Use of questions related to the crime that only the guilty person would know along only the guilty person would know along with misleading questionswith misleading questions

Misleading questions: questions about the Misleading questions: questions about the crime which are fictionalcrime which are fictional

Assumption: guilty person will show Assumption: guilty person will show heightened emotional reactivity to heightened emotional reactivity to questions related to the crime than to questions related to the crime than to misleading questionsmisleading questions

Innocent person will feel emotional Innocent person will feel emotional reactivity to all questions reactivity to all questions

Research on the Validity of the Research on the Validity of the PolygraphPolygraph

Two types of studiesTwo types of studies

• Laboratory Studies and Field Laboratory Studies and Field StudiesStudies

• Laboratory Studies - asked college Laboratory Studies - asked college students to commit a crime and students to commit a crime and then lie about itthen lie about it

Advantage of knowing the ‘truth’Advantage of knowing the ‘truth’ Lack ecological validityLack ecological validity

Research on the Validity of the Research on the Validity of the PolygraphPolygraph

Field StudiesField Studies

Include a representative sample of Include a representative sample of polygraph tests administered under polygraph tests administered under real-life conditionsreal-life conditions

Charts scored by independent polygraph Charts scored by independent polygraph examiners (blind scoring) - use of examiners (blind scoring) - use of only the charts and no additional only the charts and no additional informationinformation

Compare score of polygraph to an Compare score of polygraph to an independent criterion (some other independent criterion (some other determination of guilt or innocence)determination of guilt or innocence)

Counter-Measures to the PolygraphCounter-Measures to the Polygraph

Physical and Mental Counter MeasuresPhysical and Mental Counter Measures

PhysicalPhysical• Suppressing physiological responsesSuppressing physiological responses

• Augmenting physiological responsesAugmenting physiological responses

• Suppressing overall physical activity Suppressing overall physical activity (sedatives)(sedatives)

How Effective are Physical How Effective are Physical Counter-measures?Counter-measures?

Can result in inconclusive results Can result in inconclusive results rather than truthful resultsrather than truthful results

Use of more than one counter measure Use of more than one counter measure simultaneously is more effectivesimultaneously is more effective

Training and practice is necessaryTraining and practice is necessary

Some physical counter-measures can Some physical counter-measures can be detected by the examiner; others be detected by the examiner; others may be missedmay be missed

Mental Counter-MeasuresMental Counter-Measures

Artificially producing responses to Artificially producing responses to control questionscontrol questions

Attenuating responses to relevant Attenuating responses to relevant questionsquestions

Mental dissociationMental dissociation

• Can not be detected by examinerCan not be detected by examiner• Less effective than physical measuresLess effective than physical measures• Most effective - think of emotionally Most effective - think of emotionally arousing events during baseline arousing events during baseline questionsquestions

Is the Polygraph Effective?Is the Polygraph Effective?

• Training: certification, Training: certification, continuing educationcontinuing education

• Techniques usedTechniques used• Type of equipmentType of equipment• Admissibility to courtAdmissibility to court

Psychological AutopsiesPsychological Autopsies Psychological autopsy - determine the Psychological autopsy - determine the mode of death; typically distinguish mode of death; typically distinguish whether the cause of death was an whether the cause of death was an accident or suicideaccident or suicide

NASH classification: natural, NASH classification: natural, accidental, suicidal, or homicidalaccidental, suicidal, or homicidal

SuicideSuicide• Self-inflictionSelf-infliction• Intention to dieIntention to die

Status of expert testimony for Status of expert testimony for psychological autopsiespsychological autopsies