John Duffy Case Study
Psychology: AQA A Level, topic 16.1.5
John Duffy Case Study
John Duffy, the Railway Rapist, was a criminal case where offender profiling was successful.
The profile
- Duffy committed 24 acts of sexual assault and 3 murders between 1982 and 1986.
- David Canter (a proponent of geographical profiling) participated in this investigation.
- From the details of the crimes he developed a profile, which Duffy ended up matching very closely.
- The profile stated the following information about the offender:
Personal characteristics
- Personal characteristics.
- The offender would know about British railways:
- Duffy had worked for British rail.
- The offender would also be small and feel unattractive:
- Duffy had acne and was 5’4’’.
- The offender would be in his mid to late 20s:
- Duffy was in his late 20s.
- The offender would know about British railways:
Residential location
- Residential location.
- He would live close to the first three crimes:
- Duffy lived in the same town of Kilburn.
Criminal history
- Criminal history.
- The offender would have a criminal record with violence:
- Duffy had raped his wife at knifepoint, this was recorded by police.
Domestic traits
- Domestic and social characteristics.
- The offender would fantasise about sex and violence:
- Duffy had hard-core pornographic videos.
- The offender would also be interested in martial arts:
- Duffy was in a martial arts club.
Occupation
- Occupational and educational history.
- His occupation would be either skilled or semi-skilled:
- Duffy was a carpenter.
Strengths of John Duffy Profiling
John Duffy, the Railway Rapist, was a criminal case where offender profiling was successful.
Increased use
- In total, Duffy fit 13 out of the 17 characteristics developed by Canter.
- From there, offender profiling became much more commonplace.
Explanation
- Canter thought that behaviour is consistent.
- Therefore, the traits of the crime would be similar to the traits of the offender during their everyday life.
Behaviour
- Initially, Duffy was committing rape against his victims.
- However, he was once almost recognised and therefore started to murder the victims as well.
Learned behaviours
- Duffy was also discovered to have burned the bodies of his murder victims in an attempt to get rid of forensic evidence.
- When he was arrested for raping his wife, he learned about police procedures and therefore knew to consider this.
Test yourself on John Duffy Case Study
Which of the following was NOT true of Duffy?
Before John Duffy was caught, the offender was known as what?