offender profiling- forensic psychology Flashcards
what is offender profiling
investigative tool by police to solve crimes
main aim to narrow list of likely suspects
compiling- careful scrutiny of crime scene and analysis of other evidence to generate hypothesis about probable characteristics of offender
what is the top down approach
originated US result of work carried out by FBI in 70s- drew upon interviews with 36 sexually motivated murderers, concluded data could be categorised into organised or disorganised crimes and could predict other characteristics and used to find offender
collect data about murder and decide on category it best fits
what is the difference between organised and disorganised offenders
serious offenders have signature ways of working and generally correlate with set of social and psychological characteristics relate to individual
what is organised offender
evidence of planned crime in advance
victim is targeted suggests killer has type of victim
offender maintains high degree of control during crime and operate with detached surgical precision
little evidence or clues left behind
tend to be above average inteligence, skilled professional occuptation and socially and sexually competent, married and have children
what is disorganised offender
little evidence of planning offences may be spontaneous
crime scene reflect the impulsive nature of attack, body is usually still at scene and appears to have been very little control on the part of the offender
lower than average IQ, unskilled work or unemployed, history of sexual dysfunction and failed relationships, live alone and relatively close to where offence took place
what are the four stages to construct FBI profile
data assimilation- profiler reviews the evidence
crime scene classification- organised or disorganised
crime reconstruction- hypotheses in terms of sequence of events behaviour of victim etc
profile generation- hypotheses related to likely offender
what is research support (top down)
support for distinct organised category of offender
to test organised disorganised typology canter conducted analysis of 100 US murders committed by different serial killer, technique called smallest space analysis (statistical technique identifies correlations across different samples of behaviour), used to assess co occurence of 39 suspects of serial killings, included whether torture or restraint attempt to conceal form of murder weapon used and cause of death, analysis revealed there does seem to be subset features of serial killings which matched FBI typology for organised
key component of typology has some validity
studies suggest that organised and disorganised types not mutually exclusive
variety of combinations that occur at any murder scene
Godwin argued difficult to classify killers as one or the other type, killer may have multiple constrasting characteristics
suggests the typology more of a continuum
what is wider application (top down)
can be adapted to other kinds of crime
Meketa reports top down applied to burglary leading to 85% rise in solved cases in three US states
detection methods retains organised disorganised distinction but adds two new categories- interpersonal (offender usually knows victim and steals something of significance) and opportunistic (generally inexperienced young offender)
suggests has wider application than was assumed
what is flawed evidence (top down)
evidence which it is based weak
FBI profiling developed using interviews 36 murderers, 25 of which were serial killers, 11 being single or double murderers, at the end of process 24 classified as organised and 12 disorganised
Canter- argued that sample poor FBI didnt select random or large sample ant didnt include different types of offender
no standard set of questions each interview different and not comparable
top down doesnt have sound scientific basis
what is personality (top down)
based on principle of behavioural consistency- serial offenders characteristic ways of working
should be seen across all their crime scenes
should be possible for profilers to link two different crime scenes together making offender easier to catch
situationist psychologists- MIschel argue peoples behaviour is more driven by situation they are in rather than personality
behavioural patterns seen at crime scene may tell us little about how individual behaves in everyday life
what is bottom up approach
generate picture of offender characteristics routine behaviour and social background through systematic analysis of evidence at crime scene
profile is data driven and emerges as investigator engages in deeper and more rigorous scrutiny of details of offence
more grounded in psychological theory
what is investigative psychology
attempt to apply statistical procedures and psychological theory to analysis of crime scene evidence
aim to establish patterns of behaviour likely to occur or coexist across crime scenes
develop statistical data base then acts as baseline for comparison
specific details of offence can be matched against data base to reveal important details about offender
determine whether series of offences were linked
interpersonal coherence- the way an offender behaves at the scene reflects their behaviour in everyday situations
significance of time and place- how offender lives
forensic awareness- describes individuals who have been subject of police interrogation before- behaviour denote how mindful they are of covering their tracks
what is geographical profiling
uses info about location of linked crime scenes to make inferences about likley home or operational base- crime mappy and based on principle of spatial consistency (people commit crimes within a limited geographical space)
can be used in conjuction with pyschological theory to create hypotheses about how offender is thinking
assumption serial offenders restrict their work to geographical areas familiar with and understanding spatial pattern of their behaviour provides with centre of gravity lilely to include offenders base
Canters circle theory- pattern of offending forms circle around offenders home base, distribution of offences leads to describe offender as marauder (operates close proximity to their home base) or commuter (likely to have travelled a distance away from usual residence)
spatial decision offer team important insight into nature of the offence and factors about offender
what is evidence for investigative psychology (bottom up)
evidence supports use
canter and heritage- analysis of 66 sexual assualt caseds, data examined using smallest space analysis, several behaviours identified common in different samples of behaviour, each individual displayed characteristic pattern of behaviours and can help establish whether two or more offences committed by same person
supports basic principle that people are consistent in behaviour
case linkage depends on database and only consist of historical crimes solved
solved- straightforward crimes to link together in first place
suggests tell us little about crimes that have few links between them and remain unsolved
what is evidence for geographical profiling (bottom up)
support for geographical profiling
Lundrigan and Canter- collated info from 120 murder cases of serial killers in US, smallest space analysis revealed spatial consistency in behaviour of the killers, location of each body disposal site created centre of gravity because when offenders start from their home base they may go on different direction each time dispose of body but all different ites create circular effect around the home base, offenders base located in centre of pattern, effect more noticeable for offenders who travelled short distances
supports geographical info can be used to identify an offender
