Offender Profiling: Bottom-Up

Question 1

Bottom-Up Approach

Answer 1

1) The British bottom-up model is ‘data-driven’ and emerges as the investigator looks at the details of a particular offence.

2) The aim is to generate a picture of the offenders’ characteristics, routines and background through analysis of the evidence.

Question 2

Statistical Analysis

Answer 2

1) Statistical procedures detect patterns of behaviour that are likely to occur across crime scenes.
2) This is done to develop a statistical database which then acts as a baseline for comparison.
3) Features of an offence can be matched against this database to suggest potentially important details about the offender, their personal history, family background, etc.

Question 3

Psychological Concepts

Answer 3

1) A central concept is interpersonal coherence - the way an offender behaves at the scene ( how they ‘interact’ with the victim) may reflect their behaviour in everyday situations (e.g. controlling, apologetic, etc.).

Question 4

Geographical Profiling

Answer 4

1) The locations of crime scenes are used to infer the likely home or operational base of an offender - known as crime mapping.

2) Serial offenders restrict their work’ to areas they are familiar with (spatial consistency).

3) Location can also be used alongside psychological theory to create hypotheses about the offender and their modus operandi (habitual way of working).

Question 5

Marauder & Commuter Types

Answer 5

Canter and Larkin (1993) proposed two models of offender behaviour:

1. The marauder - operates close to their home base.
2. The commuter - likely to have travelled a distance away from their usual residence when committing a crime.

Question 6

Circle Theory

Answer 6

1) Canter and Larkin also suggest that the pattern of offending locations is likely to form a circle around the offender’s usual residence, and this becomes more apparent the more offences there are.

2) The offender’s spatial decision-making can provide insight into the nature of the offence (planned or opportunistic, mode of transport, employment status, etc.).

Question 7

Bottom-Up - Profiles

Answer 7

1) Personal Characteristics
2) Criminal History
3) Residential Location
4) Domestic & Social Life
5) Occupation & Education

Question 8

Research Support - John Duffy

Answer 8

1) Duffy committed multiple counts of sexual assault and murders.
2) Canter, from the details of the crimes, developed a profile, which Duffy ended up matching very closely.
E.g. Know about British railways, be small and feel unattractive, mid to late 20s.
–> In total, Duffy fit 13 out of the 17 characteristics developed by Canter.

Question 9

Strength of Approach

Answer 9

EVIDENCE SUPPORTS GEOGRAPHICAL PROFILING

1) Lundrigan and Canter (2001) collated - info from 120 murder cases in the US. Smallest space analysis revealed spatial consistency.

2) Offenders leave home base in different directions when dumping a body but created a circular effect, especially in the case of marauders.

–> This supports the view that geographical
info can be used to identify an offender.

Question 10

Limitation of Geo Profiling

Answer 10

GEO INFO ALONE IS NOT ENOUGH

1) Recording of crime is not always accurate,
can vary between police forces and a large number are not even reported to police.

2) Even if crime data is correct, other factors matter e.g. timing of the offence and age and experience of the offender.

–> This suggests that geographical
info alone may not always lead to the successful capture of an offender.

Question 11

Limitation to Offender Profiling

Answer 11

NOT EFFECTIVE

1) Holmes (1989) found that only 88 out of 192 cases where offender profiling was used resulted in arrest.
This is an effectiveness of only 46%.

ONLY SPECIFIC CRIMES

2) Profiles can only be used for a small amount of crimes such as rape or murder.
Crimes like theft or robbery, where the purpose is material gain, have been difficult to develop profiles from.