forensics :offender profiling - bottom up approach

Question 1

what is the bottom-up approach offender profiling

Answer 1

profilers work up from systematic analysis of evidence collected at the crime scene to create a unique picture of the offender (likely characteristics, routine behaviour, motivations and social background, for eg)

Question 2

who developed the bottom-up approach?

Answer 2

david canter

Question 3

what is investigative psychology

Answer 3

a form of bottom-up profiling matching details from the crime scene with statistical analyses of typical offender behaviour patterns, based on psychological theory

Question 4

interpersonal coherence

Answer 4

the way an offender behaves at the scene, including how they ‘interact’ with the victim, may mirror their behaviour in more everyday situations

Question 5

what is forensic awareness

Answer 5

the offender will show that they are aware of forensic investigation by cleaning up a crime scene. this could suggest they have knowledge of the criminal justice system

Question 6

geographical profiling

Answer 6

developed by kim rossmo; it’s a form of bottom-up profiling based on spatial consistency - an offender’s base and future offences can be inferred through the geographical location of previous crimes

Question 7

what is crime mapping

Answer 7

using information from the linked crime scenes to make inferences about the likely base of the offender

Question 7

define centre of gravity

Answer 7

understanding the spatial pattern of offending behaviour gives investigators a “centre of gravity” which includes their base and likely next offending locations (this is the jeopardy surface)

Question 7

define modus operandi

Answer 7

crime mapping is used alongside investigative psychology to create hypotheses about how the offender thinks and operates

Question 8

what is canter’s circle theory (canter and larkin, 1993)

Answer 8

patterns of offending usually forms circles around their residence; the more offences, the more obvious this is

Question 9

what is the marauder (model of offending behaviour in canter’s circle theory)

Answer 9

offender who operates closer to their home base

Question 9

what is the commuter (model of offending behaviour in canter’s circle theory)

Answer 9

offender who is likely to have travelled a distance away from their usual residence

Question 10

how does canter’s circle theory help identifying offenders?

Answer 10

it can give an insight into the nature of the offence planned vs opportunistic, offenders’ mental maps, mode of transport, employment status, approximate age etc

Question 11

limitation : why does the case of rachel nickell provide evidence against both types of profiling?

Answer 11

the investigation targeted colin stagg, a local, who fit the offender profile and he found to be wrongly convicted, ‘honey trap’ was used and he didn’t confess to murder and in 2008, following new forensic evidence, robert napper was convicted of rachel’s murder. napper had been ruled out earlier because he wasn’t tall enough to fit the profile **** continue

Question 12

strength : how does canter and heritage (1990) study support the effectiveness of investigative psychology?

Answer 12

• conducted an analysis of 66 sexual cases using smallest space analysis (a computer program that identifies correlations across patterns of behaviour)
• they found that several behaviours were noticed in different patterns for different individuals (eg, impersonal language, lack of reaction towards victim etc)
• this can be used to understand how an offenders behaviour may change over time or help investigators establish whether several offences were committed by the same person
• this is important as it shows how statistical techniques can be used within investigative psychology for a useful purpose
• this means that the bottom-up approach is a valid way of profiling and narrowing down offenders; has had a positive impact on psychology and offender profiling

Question 13

strength : why does evidence from lundrigan and canter (2001) support the effectiveness of geographical profiling?

Answer 13

• a strength of the bottom-up approach is that it has evidence supporting geographical profiling
• lundrigan and canter (2001) collated information frm 120 serial murder cases in the usa
• using smallest space analysis, they found that there was a high degree of spatial consistency in the offenders’ behaviours with a centre of gravity where the offender’s base was
• this effect was more pronounced for marauders]
• this is important because geographical profiling can accurately locate where the offender lives
• this means that geographical profiling is a useful way and has has proved valuable in bottom-up profiling

Question 14

limitation : what are the mixed results for the utility of bottom-up profiling, how is this a criticism?

Answer 14

• a limitation of bottom-up profiling is that there are mixed results for the utility of bottom-up profiling
• copson (1995) analysed 48 police forces and found the advice from bottom-up profiling was useful 83% of the time but only helped lead to accurate identification of the offender in 3% of cases
• kocsis et al (2002) found chemistry students created a mire accurate offender profile than bottom-up analysts
• this is important because it’s suggesting the bottom-up approach lacks accuracy
• this means that the approach may not be the best approach to narrowing down offenders