Offender profiling
Offender profiling:
• Identifies characteristics of an offender by examining the crime and crime scene
• Reduces down the number of suspects rather than catching the culprit
• 2 types → typology (top-down) and data-driven (bottom-up)
M
Crime Investigator
scene (profilers)
Typology approach:
• aims to solve some of the most extreme murderers cases *
• Based on police experience + case studies (not stats/theories)
• Interviews with 36 serial killers including Ted Bundy
• Forms a template for future crimes
Key stages of the typology approach:
1. Data assimilation - crime scene, the nature of crime, victim
2. Crime scene organisation - organised or disorganised
3. Criminal profile created - redisendece, motivation, relationship, age, gender, ethnicity etc.
4. Crime assessment - share with the police to aid investigation
Organised offenders
T
Disorganised offenders
• orderly life • lives alone, near crime scene
• Average-high intelligence • Below average intelligence
• Socially competent • Socially incompetent
• Skilled employment • Unskilled employment
• Plans offences • Little preparation
• Uses restraints • Unlikely to use restraints
• Brings + removes weapon • Improvises + leaves weapon
• Concealment of evidence • Limited attempt at
concealment
Ao3 evaluation - typology approach:
Third profile?
• Canter et al (2004) - 100 real life serial killer cases
◦ No clear division between organised and disorganised offenders - need for “mixed” category
Methodology:
• Interviews with 36 serial killers
◦ Not typical of other killers- is applying them “typical” murderers valid?
• Self report study → validity - social desirability etc
Accuracy:
• Alison et al (2003) - judgements of offender profiles are not accurate
◦ Police officers were given fake + real profiles and asked to rate them
Usefulness:
Copson (1995) - 184 USA police officers
• 82% said it was useful + 90% said they’d use it again
• May open up avenues for profiling
Data-driven approach:
• Canter (1990) - data driven
• Uses statistical techniques to predict offender characteristics
• Based on crime scene evidence first, not experience/beliefs of profiler
, The railway rapist:
• 1986 - 24 sexual offences over 4 years
• December 1985 + spring 1986 - 2 murders (police watching crimewatch noticed connection)
• Police started manhunt
◦ John Duffy was on a list of 2000 suspects as number 1505
◦ Police watched him because he fit profile → behaviour suggested he was the killer
◦ Arrested and sentenced to life
Investigative psychology:
Interpersonal coherence:
• Believes behaviour is consistent
• There will be links between elements of the crime and everyday behaviour
• Behaviour can change over time - profilers will look for gradual patterns of change between offences carried
Forensic awareness:
• some behaviours may indicate awareness of police forensic techniques + offenders’ past experiences the- eg. Rapists who conceal
fingerprints often have a previous conviction for burglary
Ao3 - investigative psychology:
Conviction rates:
Copson (1995) - 48 UK police forces using this method
• over 75% of police officers said it was useful
• However, only 3% of cases led to identification of the offender
Geographical profiling
• location can be revealing- belief that offenders commit crimes near significant locations
Brantingham’s crime site selection:
*
Ao3 evaluation - geographical profiling:
Usefulness:
Rossmo (1999) - helpful in prioritising house to house searches
Usefulness:
Turvey (2011) - dismissed geographical prophilling from use in Vancouver Police department → wasn’t beneficial
• Cannot distinguish between multiple offenders in same area
Offender profiling:
• Identifies characteristics of an offender by examining the crime and crime scene
• Reduces down the number of suspects rather than catching the culprit
• 2 types → typology (top-down) and data-driven (bottom-up)
M
Crime Investigator
scene (profilers)
Typology approach:
• aims to solve some of the most extreme murderers cases *
• Based on police experience + case studies (not stats/theories)
• Interviews with 36 serial killers including Ted Bundy
• Forms a template for future crimes
Key stages of the typology approach:
1. Data assimilation - crime scene, the nature of crime, victim
2. Crime scene organisation - organised or disorganised
3. Criminal profile created - redisendece, motivation, relationship, age, gender, ethnicity etc.
4. Crime assessment - share with the police to aid investigation
Organised offenders
T
Disorganised offenders
• orderly life • lives alone, near crime scene
• Average-high intelligence • Below average intelligence
• Socially competent • Socially incompetent
• Skilled employment • Unskilled employment
• Plans offences • Little preparation
• Uses restraints • Unlikely to use restraints
• Brings + removes weapon • Improvises + leaves weapon
• Concealment of evidence • Limited attempt at
concealment
Ao3 evaluation - typology approach:
Third profile?
• Canter et al (2004) - 100 real life serial killer cases
◦ No clear division between organised and disorganised offenders - need for “mixed” category
Methodology:
• Interviews with 36 serial killers
◦ Not typical of other killers- is applying them “typical” murderers valid?
• Self report study → validity - social desirability etc
Accuracy:
• Alison et al (2003) - judgements of offender profiles are not accurate
◦ Police officers were given fake + real profiles and asked to rate them
Usefulness:
Copson (1995) - 184 USA police officers
• 82% said it was useful + 90% said they’d use it again
• May open up avenues for profiling
Data-driven approach:
• Canter (1990) - data driven
• Uses statistical techniques to predict offender characteristics
• Based on crime scene evidence first, not experience/beliefs of profiler
, The railway rapist:
• 1986 - 24 sexual offences over 4 years
• December 1985 + spring 1986 - 2 murders (police watching crimewatch noticed connection)
• Police started manhunt
◦ John Duffy was on a list of 2000 suspects as number 1505
◦ Police watched him because he fit profile → behaviour suggested he was the killer
◦ Arrested and sentenced to life
Investigative psychology:
Interpersonal coherence:
• Believes behaviour is consistent
• There will be links between elements of the crime and everyday behaviour
• Behaviour can change over time - profilers will look for gradual patterns of change between offences carried
Forensic awareness:
• some behaviours may indicate awareness of police forensic techniques + offenders’ past experiences the- eg. Rapists who conceal
fingerprints often have a previous conviction for burglary
Ao3 - investigative psychology:
Conviction rates:
Copson (1995) - 48 UK police forces using this method
• over 75% of police officers said it was useful
• However, only 3% of cases led to identification of the offender
Geographical profiling
• location can be revealing- belief that offenders commit crimes near significant locations
Brantingham’s crime site selection:
*
Ao3 evaluation - geographical profiling:
Usefulness:
Rossmo (1999) - helpful in prioritising house to house searches
Usefulness:
Turvey (2011) - dismissed geographical prophilling from use in Vancouver Police department → wasn’t beneficial
• Cannot distinguish between multiple offenders in same area
