Creating a profile

Canter's study - Organised and Disorganised theories of serial murder

Aim: To test the reliability of organised/disorganised typologies.

Methodology:

• A content analysis using a multi-dimentional scaling method was applied to 100 cases

Cases came from published accounts of serial killers in the USA and were cross checked with court reports etc when possible and were collected over several years by independent researchers.

This was to find out if the features hypothesised to belong to each typology would be consistently and distinctively different.

Results:

• Twice as many disorganised as organised - suggesting disorganised offenders are more common.
• 70% a body was concealed
• 75% sexual activity occured

Canter and Heritage study - Developing offender profiling

Aim: To identify a behaviour pattern from similarities between offences

Methodology:

• Content analysis of 66 sexual offences from various police forces - committed by 27 offenders
• They were conducted to find 33 offence variables that were clearly linked to a potential behaviour characteristic

--> The data was subjected to a small space analysis.

Results: The following variables were found to be central to the 66 cases...

• Surprise attack
• Vaginal intercourse
• Impersonal language
• No reaction to victim
• Victims clothes disturbed

Canter - The case of John Duffy

In November 2000, John Duffy, who was serving life for the **** and murder of several women, confessed that he was responsible for many more and that he had committed some with an accomplice, David Mulcahy.

John Duffy had been interviewed by the police for an unrelated offence, a 'domestic' against his ex-wife, which bore similarities to the attacks to the women in the case. He was one of 2000 suspects connected to the crime by blood groups. He lived in Kilburn North London, had worked on the railways as a carpenter and was the right age. The profile did fit on these criteria.

However, Duffy was a lot shorter than the victims remembered and many had described him as having black or even ginger hair. But police, suggest that the 'weapn effect' may have played a part as he threatened victims with a knife. 

This profile represents the first attempt to use behavioural characteristics to search for a criminal instead of purely forensic evidence from the crime scene. Canter identified 17 profiler points...later it was found that the perpretator matched 13/17 profile points.