Psychology and Investigations

Chapter 12

Psychologist’s Contributions

Investigative inferences Offender profiling, geographical profiling,

correlates of offence style Investigative and legal process

Interviewing, predication of violence Assessment of investigative and legal

informationEyewitness testimony, detecting deception

Criminal Profiling Criminal profiling is a technique for

identifying the personality and behavioural features of an offender based on an analysis of the crimes they have committed

Most frequently used in homicide and rape cases

Assumptions

Individual behaviour and motivation can be predicted from the study of individuals who share similar behaviour and motivations

Hypothesizes about demographic, motivational, & psychological features of the crime and offender

Criminal Profile Analysis

Still at the crossroads between art or sciencePopularity stems from films and television and

few well publicized cases The Silence of the Lambs Copycat Mindhunters The X-Files Criminal Minds

Can it be an efficient investigative technique?Can it be studied scientifically?

Noted Experts

James A. Brussel John Douglas Robert Ressler Roy Hazelwood David Canter

The Purposes of Profiling

Provide characteristics of the offender Help analyze, understand crime scene Provide leads for investigators to follow Narrow the pool of viable subjects Prioritize investigation of subjects Develop interview, interrogation strategies Show links between crimes Provide supportive trial testimony

The Value of Profiling Surveys of police officers indicate profiling is

useful in investigations (provides clues) Benefits of profiles include:

Provide a greater understanding of the case

Reinforce judgements about the offender Only 2.6% of respondents indicated that

profiles led to the identification of the offender

Challenges of Profiling

Turning info from crime scene into estimates of personality, age, work habits, of offender

Modern personality tests can’t do this Not a scientific enterprise – largely

intuition, experience Not thoroughly evaluated – utility unclear

Potential Problems with Profiling Many forms of profiling are based on a

model of personality (the classic trait model) that lacks empirical support

Profiles often contain ambiguous advice and such advice can be interpreted to fit a wide range of suspects

Professional profilers do not always produce profiles that are more accurate than the profiles produced by novices

What Do We Know About Profiling?

Crime scenes can often be accurately classified into broad categories (planned)

Sometimes reveal info about a murderer (whether or not he knew his victim)

Profiling may be useful in solving crimes with strong sexual component (sexual killings) Revealed in killer’s “signature” activities

Different profilers may produce different profiles Not yet based on clear, systematic procedures

So What Don’t We Know?

No good estimates of how often profiles have been useful or how often useless or counterproductive

Error rates or rates of success difficult to evaluate Some have led to arrest of guilty suspects Some have led to arrest of innocent people Some have pointed police in right direction Some have led police astray and wasted time and resources

Misuse of profiles poses clear dangers! Subjective, stereotypical, or inaccurate profiles may lead to charges Judges may use own profiles to decide what testimony to admit Jurors may be guided by subjective profiles