bottom up Flashcards
Offender profiling
Criminal profiling’, a behavioural and analytical tool that is intended to help investigators accurately predict and profile the characteristics of unknown offenders
The bottom-up approach
Work up from evidence from crime scene to develop hypotheses
British - data-driven
Aim of bottom-up approach
Generate a picture of offender characteristics, routine behaviour and social background through systematic analysis of evidence
Investigative psychology
Form of bottom-up approach
Establishes patterns of behaviour forming a statistical ‘database’
Interpersonal coherence
Offender’s behaviour at crime scene reflects their everyday behaviour and thus is a clue
Rapists may want to maintain maximum control and humiliate their victims while others are more apologetic - Dwyer
Forensic awareness
Individuals who have been subject of police interrogation before ‘cover their tracks’
Geographical profiling
Form of bottom-up approach
Location of crimes can be used as a clue - based on principle of spatial consistency
Crime mapping based on psychological theories of offender’s behaviour in relation to their home base
Canter’s circle theory
Marauders operate close to home
commuters operate a further distance away from their usual residence
What is smallest space analysis
A statistical technique for creating a visual representation of data, in which more closely correlated variables are grouped together
Case study
Railway Rapist - Canter assisted in capturing
Duffy - one of 2000 suspects, after the profiling he became one of two.
Profiled - Lives in Kilburn, marriage problems, small, martial artists
Duffy - Lives in Kilburn, separated, 5ft4, member of martial arts club
Accurate profile
EVAL - evidence for investigative psychology
P - strength as evidence to support it
E - Canter and Heritage - analysis of 66 sexual assault cases - examined using smallest space analysis
E - several behaviours were identified such as impersonal language and lack of reaction to victim - each individual displayed a characteristic pattern of such behaviours - helps to establish whether two or more offences were committed by the same person
L - supports one of the basic principles of investigative psychology - that people are consistent in their behaviour
P - however - case linkage depends on database - only consist of historical crimes that have been solved
E - when solved it may have been because they were straightforward to link
E - this causes a circular argument
L - investigative psychology may tell us a little about crimes that have few links between them and therefore remain unsolved
EVAL - evidence for geographical profiling
P - strength as evidence supports geographical profiling
E - Lundrigan and Canter - collated information from 120 murder cases involving serial killers in the US using smallest space analysis
E - spatial consistency was found - location of each body disposal site created a ‘centre of gravity’ as offenders start from home base and go in a different direction each time creating a circular effect around the home base - effect more noticeable in marauders
L - supports the view that geographical information can be used to identify an offender
EVAL - geographical information insufficient
P - Limitation as geographical profiling may not be sufficient on its own
E - success may be reliant on quality of data the police can provide, which is not always accurate. About 75% of crimes are not reported to police - DFC
E - questions the utility of an approach that relies on accuracy of geographical data and even if information is correct, critics claim that other factors are just as important such as timing of offence, age and experience of offender - Ainsworth
L - geographical information alone may not always lead to the successful capture of an offender
EVAL - mixed results
P - offender profiling has a mixed history and is regarded in different ways by police forces
E - Copson - surveyed 49 police departments - advice provided by profiler was judged to be useful in 83% of cases - valid investigative tool
E - same study revealed in only 3% of cases did it lead to accurate identification of offender - Rachel Nickell case - reminder of how profiling can be misused - Kocsis et al found that chemistry students produced more accurate offender profiles on a solved murder case than experienced senior detectives
L - may question whether the approach is worthwhile