Lecture 4: Crime Linkage

Question 1

What is linking crimes?

Answer 1

-Identification of crimes believed to be committed by same offender as a result of their behavioural similarity

Question 2

Why do we link crimes?

Answer 2

• Target offenders
• Saves police resources
• Accumulation of evidence from different crime scenes
• Victims gain credibility from other victims
• Expert evidence in court

Question 3

The process of a crime analyst

Answer 3

• Request and read documentation about offence
• Construct list of behaviours for that offence
• Search for similar cases
• Construct list of behaviours for other similar offences
• Identifity similar and dissimilar behaviours
• Weight similarities
• Write report for police
• May have to go to court

Question 4

Data bases for linking crimes

Answer 4

• Use ViCLAS = violent crime linkage analysis system = developed to avoid linkage blindness
• Coding and analysis process done by analysts = not automatic process

Question 5

Assumption of ViCLAS

Answer 5

-If assumptions not met crime linkage wont work

Offender consistency
–> Offenders will be mostly consistent in behaviour across crimes

Offender distinctiveness:
–> Needs to be variation between offenders in the way they commit an offence

Question 6

State of New Jersey vs Steven Fortin (2000)

Answer 6

• Fortin convicted of attempted murder and rape
• Unresolved murder had similarities to previous convictions
• Linkage analysis done = 15 shared behaviours
• Court not happy with scientific background of linkage analysis so case overturned
• DNA analysis used in the end

Question 7

Criteria to use crime linkage in court

Answer 7

• Testable hypothesis
• Must have been tested
• Subject to peer review and publication
• Should know the error rate
• Should have widespread acceptance within scientific community

Question 8

Personality psychology

Answer 8

• Interested with whether people are consistent with behaviours over time and situations
• Cognitive affective personality system = after debate came to recognise it was mixture of situation and personal characteristics

Question 9

Critique of crime linkage literature

Answer 9

• Hard to test in environment close to real life
• Most research involves solved crime = doesn’t reflect reality
• ->BUT recent research starting to test crime linkage with samples of unsolved crime linked to DNA evidence = suggested less effective with unsolved crime
• Often studies use serial crimes = doesn’t reflect reality
• Analysts searching for linked crimes with large datasets = most studies have much smaller sample sizes