forensics AI Flashcards
(88 cards)
define profiling
A behavioural and analytical tool that is intended to help investigators accurately predict and profile characteristics of unknown criminals
The main aim of offender profiling is to narrow the field of enquiry and the list of likely suspects
what are the two elements of bottom up profiling
investigative psychology
geographical profiling
define bottom up profiling
profilers work up from the evidence collected from the crime scene to develop hypotheses about the likely characteristics , motivations and social background of the offender
define investigative psychology
a form of bottom up profiling that matches details from the crime scene with statistical analysis of typical offender behaviour patterns based on psychological theory.
define geographical profiling
a form of bottom-up profiling based on the principle of spatial consistency ; that an offenders operational base and possible future offences are revealed by the geographical location of their previous crimes
outline investigative psychology as a form of bottom up profiling
investigative psychology attempt to apply statistical procedures alongside psychological theory to analysis of crime scene evidence. the aim in relation to offender profiling , to establish patterns of behaviour that are likely to occurr or co-exist across crime scenes.
This is done to develop a statistical ‘database’ which then acts as a baseline for comparison. specific comparison can be then matched against this database to reveal important details about the offender.
this may also determine whether a series of offences are linked in that they are likely to have been commited by the same profile.
outline geographical profiling as a form of the bottom up approach
geographical profiling uses information to do with the location of linked crime scenes to make inferences about the likely home or operational base of an offender - known as crime mapping
Location can also be used alongside psychological theory to create hypotheses about how the offender is thinking as well as their modus operandi
• The assumption is that serial offenders restrict their ‘work’ to areas that they are familiar with , therefore understanding the spatial pattern of their behaviour provides investigators with a centre of gravity , which may help investigators make educated guesses about where the offender is likely to strike next called the jeapordy surface
what is canters circle theory for 2 models of offending behaviour - bottom up approach
The marauder – operates close to their home base.
The commuter – likely to have travelled a distance away from their usual residence when committing a crime.
outline one strength of geographical profiling - supporting evidence
one strength of geographical profiling is that there is supporting evidence. for example Lundrigan & Canter (2001) collated information from 120 murder cases involving serial killers in the US. The location of each body disposal site was plotted, and a ‘centre of gravity’ identified. this is a strength of geographical profiling as it shows spatial information is a key factor in determining the base of an offender, therefore it is assumed that this is a valid method of offender profiling
outline one strength of the bottom up approach- objective and scientific
one strength of the bottom up approach to offender profiling is that it is more objective and scientific. for example due to the advances in artificial intelligence, investigators can manipulate geographical , biographical and psychological data quickly to produce insights that assist the investigation. this means that the bottom up approach is more grounded in evidence and theory and less driven by speculation and hunches. the impact of this should be that offenders are more quickly and accurately identified in investigations
outline one strength of investigative psychology - supporting evidence
There is evidence to support investigative psychology. Canter & Heritage (1990) did a content analysis of 66 sexual assault cases using smallest space analysis. Several characteristics were identified in most cases e.g. use of impersonal language
outline one limitation of the bottom up approach - better at narrowing down than identifying
one limitation of the bottom up approach is that there are issues with offender profiling. for example in Rachel nickells death the original suspect had been ruled out of the enquiry at an early stage because he was several inches taller than the profile which had been created through the bottom up approach. this suggest that profiling may lead the investigation in the wrong direction if considered too literally. it may mean that bottom up approach may be more effective at narrowing down a list of offenders rather than identifying the assailant.
outline one limitation of the bottom up approach - mixed support
one limitation of the bottom up approach is that there is mixed support from studies into the effectiveness of offender profiling. for example Copson (1995) surveyed 48 police forces- advice provided by a profiler was judged ‘useful’ in 83% of cases but led to accurate identification of an offender in just 3% of cases. this means that there are some significant issues with the reliability and accuracy of the bottom up approach to profiling which may make it inaccurate to use when identifying offenders
define the top down approach
profilers start with a pre established typology and work down in order to assign offenders to one of two categories based on the witness accounts and evidence from the crime scene.
define organised offender
an offender who shows evidence of planning , targets the victim and tends to be socially and sexually competetent with higher than average intelligence
define 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
define offender profiling
also known as criminal profiling a behavioural and analytical tool that is intended to help investigators accurately predict and profile the characteristics of unknown criminals.
Outline the top down approach
the top down approach originated in the US. it is also known as the typology approach , offenders who use this method will match what is known about the crime scene and the offender to a pre existing template that the FBI developed. murdereres and rapists are classified into one of two categories organised or disorganised on the basis of evidence which informs the subsequent police investigation
what are the two categories used in the top down approach to categorise offenders
organised offenders and disorganised offenders
outline organised offenders
they show evidence of having planned the crime scene in advance , the victim is deliberately targetted and will often reflect on the idea the offender has a type. they maintain a high degree of control during their crime and operate with precision.
socially and sexually competetent
above average IQ
married with children
outline disorganised offenders
disorganised offenders show little evidence of planning , suggesting the offence may have been spontaneous , spur of the moment act. teh crime scene tends to reflect the nature of the attack- the body is still left at the crime scene and their appears to be little control on the part of the offender.
-unskilled unemployed
lower than average IQ
history of sexual dysfunction and failed relationships
live alone and relatively close to the offense
what are organised and disorganised offenders based on the idea of
organised and disorganised offenders is based on the idea that serious offenders have a signature way of working (modus operandi) and these generally correlate with a particular set of social and psychological characteristics which relate to the individual
what are the four main stages to constructing an FBI profile
stage 1 - data assimilation the profiler reviews the evidence (e.g crime scene photographs)
stage 2 - crime scene classification - as either organised or disorganised offender
stage 3 - crime scene reconstruction - hypothesis in terms of sequence of events , behaviour of the victim e.t.c
stage 4 - profile generation - hypotheses related to the likely offender e.g physical characteristics
outline one strength/limitation of the top down approach to offender profiling - supporting evidence
one strength of the top down approach is that it has supporting evidence . for example canter found evidence of a distinct organised type , he analysed data from 100 USA murders using the smallest space of analysis where details of each case were examined with reference to 39 characteristics thought to be typical of organised and disorganised killers. this provides some support for the top down approach , however there was no evidence for a distinct disorganised type. this undermines the classification system as a whole as it questions its validity