Bottom Up (forensics)

Question 1

Strengths of bottom up

Answer 1

+ Canter and heritage - 66 sexual assault cases, satay examined using small space analysis, found common behaviours such as lack of reaction to victim - supporting investigate psychology that people are consistent in their behaviour

+ Lundrigan and Canter - 120 murder cases with serial killers in the USA, found spatial consistency in the behaviour of the offenders, more noticeable in marauders - spatial information is a key factor in identifying an offender

Question 2

How is bottom up done

Answer 2

Uses analysis of the crime scene to generate a picture of the offender e.g characteristics, social background
- does NOT start with fixed typologies

Question 3

Why is the profile data driven

Answer 3

Emerges as a result of an in depth and rigorous scrutiny of the crime scene

Question 4

Weaknesses of bottom up

Answer 4

• Some significant failures - Copson surveyed 48 police forces –> advice provided by the profiler was useful in 13% of cases, but in only 3% did it lead to accurate identification of the offender.
• Geographical profiling may not be significant enough on its own –> its successes may be reliant on the quality of the data and the police provider, which isn’t always accurate as it is estimated that 75% of crimes aren’t always reported to the police.

Question 5

What is the features of the bottom up approach?

Answer 5

1.) Investigative psychology
2.) Geographical profiling

Question 6

What does investigative psychology involve?

Answer 6

• Working up from evidence collected at the crime scene
• Invesigative psychology = statistical analysis + psychological theory
• Aims to establish patterns
• Creation of a statistical database for comparisons
  –> Matches up specific details against the database to reveal important details e.g. family background, and can also reveal if a series of offences are linked.

Question 7

What does geographical profiling involve?

Answer 7

• Crime Mapping
• Canter circle theory
  1.) The Marauders: the offender operates in close proximity to their home base.
  2.) The Commuter: the offender is likely to have travelled a distance away from their residence.

Question 8

What is crime mapping?

Answer 8

• An offenders operational base of possible future offences are revealed by the geographical location of their previous offences.
• Based on principle of spatial consistency (people commit crimes in limited geographical areas)
• Used in conjunction to psychological theory to create a hypotheses about how the offender is thinking and the MO

Question 9

What is the canter circle theory?

Answer 9

• People operate within a limited spatial mind set that creates imagined boundaries which crimes are likely to be committed.