Criminal Investigative Criminal Investigative TechniquesTechniques

Criminal ProfilingCriminal Profiling

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

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

psychologistspsychologists

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

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

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 activities Examination of background and activities

of victimsof 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 by analysis is used by criminal profilers to criminal 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 effectsparticipants, small experimental effects

The Polygraph TechniqueThe Polygraph Technique The Lie DetectorThe Lie Detector

Uses for the polygraphUses for the polygraph

• Assess honesty of exculpatory statements Assess honesty of exculpatory statements given by subjectsgiven 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 accuracyMislead subjects about test’s accuracy• Create anxiety in subjects to encourage Create anxiety in subjects to encourage

confessionsconfessions• Violate subject’s privacyViolate subject’s privacy

The Procedures involved in The Procedures involved in Polygraph TestingPolygraph Testing

Electrodes are used to record physiological Electrodes are used to record physiological changes during an interviewchanges during an interview

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

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

Sources of Inaccuracy in TestingSources of Inaccuracy in Testing

Two potential sources of inaccuracyTwo potential sources of inaccuracy

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

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

Quantifying Physiological Quantifying Physiological ResponsesResponses

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

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

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

Techniques used in TestingTechniques used in Testing

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

• Consists of approximately 10 questionsConsists of approximately 10 questions

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

Control Questions TechniqueControl Questions Technique• Assumption is that relevant questions will Assumption is that relevant questions will

generate more emotional reactivity than generate more emotional reactivity than control questionscontrol questions

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

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

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

• Guilty person will show more reactivity to Guilty person will show more reactivity to relevant questions than control 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 at hand Relevant questions deal with issue at hand

(crime, security, etc.)(crime, security, etc.) Irrelevant question is innocuousIrrelevant question is innocuous

The Relevant-Irrelevant TestThe Relevant-Irrelevant Test AssumptionsAssumptions

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

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

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

A Third ApproachA Third Approach Use of questions related to the crime that only Use of questions related to the crime that only

the guilty person would know along with the guilty person would know along with misleading questionsmisleading questions

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

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

Innocent person will feel emotional reactivity to Innocent person will feel emotional reactivity to all questions 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 StudiesLaboratory Studies and Field Studies

• Laboratory Studies - asked college Laboratory Studies - asked college students to commit a crime and then lie students to commit a crime and then lie about itabout 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 real-life polygraph tests administered under real-life conditionsconditions

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

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 rather Can result in inconclusive results rather than truthful resultsthan 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 be Some physical counter-measures can be detected by the examiner; others may be detected by the examiner; others may be missedmissed

Mental Counter-MeasuresMental Counter-Measures

Artificially producing responses to control Artificially producing responses to control questionsquestions

Attenuating responses to relevant questionsAttenuating responses to relevant questions

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 arousing Most effective - think of emotionally arousing

events during baseline questionsevents during baseline questions

Is the Polygraph Effective?Is the Polygraph Effective?

• Training: certification, continuing Training: certification, continuing educationeducation

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

Psychological AutopsiesPsychological Autopsies Psychological autopsy - determine the mode Psychological autopsy - determine the mode

of death; typically distinguish whether the of death; typically distinguish whether the cause of death was an accident or suicidecause of death was an accident or suicide

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

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

Status of expert testimony for psychological Status of expert testimony for psychological autopsiesautopsies