Forensic Psychology - Offender profiling Flashcards
Offender Profiling
Investigative techniques that are used by the police to generate hypotheses about the probable characteristics of unknown criminals by examining the characteristics of the crime scene and the crime itself.
Organised Offender
An offender who shows evidence of planning, targets the victim and tends to be socially and sexually competent with higher than average intelligence
Disorganised Offender:
An offender who shows little evidence of planning, leaves clues and tends to be socially and sexually incompetent with lower than average intelligence
The Top-Down Approach
Qualitative approach to offender profiling due to looking at the overall picture and using typologies based on police experience and case studies rather than psychological theory
Suitable for the more extreme/unsual crime - murder, rape and ritualistic crimes
Origin of the top-down approach
Began with the FBI in the US where they began researching the family background, personalities and motives of serial killers in the 1970s.
They interviewed 36 imprisoned serial killers includes Charles Manson and Ted Bundy to create a classification system for various crimes
Top-down approach - constructing an FBI profile involves:
Data assimilation: the profiler reviews the evidence (e.g crime scene photographs, reports)
Crime scene classification: as either organised or disorganised
Crime reconstruction: hypothesis in terms of the sequence of events, behaviour of the victim
Profile generation: hypothesis related to likely offender (e.g background, physical characteristics)
Strength of the top-down approach
Organised/disorganised distinction is used as a model for professional profilers in the US and has widespread support.
Evidence of effectiveness: Arthur Shawcross murdered 11 prostitutes. He was profiled as a white male, low paid job, cheap car, married and works near the river where police waited for him to return to the crime scene and the profiling was correct.
Top-down limitation - applicability
Top-down profiling is best suites to crimes scenes that reveal important details about the suspect such as rape, arson and cult killings.
More common offenses such as burglary and fraud do not let lend themselves to profiling because the resulting crime reveals littler about the offender therefore it is a limited approach to identifying a criminal
Top-down limitation - original sample
The typology approach was developed using interviews with 36 killers in the US which a small and unrepresentative sample upon to base a typology system on
Canter also argues that its not sensible to rely on self-report data with convicted killers as the data is prone to social desirability bias where respondents may exaggerate certain events or hide certain details.
Top-down limitation - classification
Tuvey suggests that these categories of disorganised/organised killers are not dichotomous, rather, they are on a continuum and can overlap.
The fact that disorganised offenders cannot be identified as distinctly different from organised offenders suggests that this system lacks validity and breadth.
Bottom Up Approach
Profiling is based on scientific theory and research
David Canter - Main researcher in this field
Two main types:
1) Investigative Psychology
2) Geographical Profiling
Investigative Psychology involves…
1) Interpersonal coherence: Looking out for correlations in peoples behaviour
2) Significance of time and place: A key variable e.g. with geographical location this can indicate where an offender is living.
3) Forensic awareness: certain behaviours deduced from the crime scene e/g concealing fingerprints analysis may reveal awareness of particular police techniques
Geographical Profiling
an offender’s operational base of possible future offences are revealed by the geographical location of their previous crimes.
Canter’s Circle Theory
People operate within a limited spatial mindset that creates imagined boundaries in which crimes are likely to be committed so this gives clues as to where the offender lives and works or will commit their next crime.
Types of offender behaviour:
1) The Marauder: the offender operates in close proximity to their home base
2) The Commuters: the offender is likely to have travelled a distance away from their usual residence
Bottom-up approach - duffy
John Duffy “The Railway Rapist”
Duffy committed 24 sexual attacks and 3 murders in railways stations across North London
Canter analysed geographical information and used investigative psychology to draw up an accurate profile. He successfully predicted Duffy lived in Kilburn, had marriage problems and was physically small/unattractive.
