Offender profiling

• Offender profiling

  Investigative tool used by police when solving crimes to narrow down likely suspects
• Top-down approach

  Originated in the US from the FBI in the 1970s.Collect data about a murder and then decide the category of data it fits the best.
• FBI's behavioral science unit study

  Looked at data from in depth inteviews of 36 sexually motivated murderers. - included Ted Bundy.

  Conclusions:

  Data could be categorised into organised and disorganised crimes.Use this to predict characteristics amd find the offender.
• Modus operandi

  Offenders signature 'way of working'

  Generally correlate with a set of social and psychological characteristics that relate to the individual.
• Organised offender

  Planned the crime in advance.

  Victim is deliberately targeted - suggest they have a 'type'.

  High degree of control

  Little evidence/clues at the crime scene.

  High IQ, well payed job.

  Have strong relationships.
• Disorganised offender

  Little evidence of planning.

  Spontaneous attacks, may attack someone they know.

  Crime scene shows impulsive nature, body normally left.

  Low control.

  Low IQ, poor job, history of failed relationships.
• Features of the FBI profile

  Has 4 stages

  1. Data assimilation - profiler reviews evidence
  2. Crime scene classification - organised or disorganised
  3. Crime reconstruction - hypotheses in terms of sequence of events, behaviour of the victim etc.
  4. Profile generation - hypothesis related to likely offender.
• Strength of top down approach (research support)

  Canter et al

  Conducted analysis of 100 US murders committed by different serial killers.

  Used smallest space analysis to find the co-occurrence of 39 aspects of serial killings. e.g. torture, attempt to conceal.

  Found there is a subset of features for serial killings that matched FBI typology for organised offenders.
• smallest space analysis

  statistical technique that identifies correlations across different samples of behaviour
• Counterpoint to research support.

  Organised and disorganised aren't mutually exclusive.

  Combinations at murder scenes.

  Godwin argues...it is difficult to classify killers.

  May have contrasting characteristics.
• Strength of top down approach (wider application)

  Adapted to other types of crime. e.g. burglary

  Meteka reported top-down profiling had been applied to burglary.

  85% rise in solved cases in 3 US states.

  Adds 2 new categories (interpersonal and opportunistic)
• Limitation of top-down approach (flawed evidence)

  FBI developed idea by looking at 36 murderers, 25 were serial killers. 24 classified as organised, 12 disorganised.

  Canter et al argued that it was a poor sample.

  Didn't use a random/large sample, didn't include range of offenders

  Interview wasn't standardised.

  No sound scientific basis
• Bottom-up approach

  Profilers work up from evidence collected from the crime scene to develop a hypotheses about likely characteristics and the background of the offender.
• Investigative psychology

  Matches details from the crime scene with statistical analysis of typical offender behaviour patterns based on psychological theory.
• Features of investigative psychology

  Interpersonal coherence = way the offender behaves at a scene.

  Significance of time and place = may indicate where offender is living.

  Forensic awareness = describes individuals who have been in police interrogation before so may be mindful about 'covering their tracks'.
• Support for investigative psychology: Research evidence

  Canter + Heritage:

  Analysis of 66 sexual assault cases.

  Data used smallest space analysis, which showed results of characteristic patterns in different offenders.

  Supports basis of IP which is people are consistent in behaviour.
• Counterpoint to research evidence for IP

  Case linkage depends on the database.

  Only works if previous crimes have been solved and therefore would be straightforward to link to new crimes.
• Geographical profiling

  Uses information about the location of crime scenes to make inferences about the home/operational base of the offender. Can be used with psychological theory.

  Based on principle of spatial consistency.

  'Centre of gravity
• Spatial consistency

  People commit crimes within a limited geographical space.
• Canter's circle theory

  Pattern of offending forms a circle around the offender's home base.
• Types of offenders (geographically)

  Marauder = operates in close proximity to their home base.

  Commuter = Travelled a distance away from home base.
• Support for geographical profiling: Research evidence

  Lundrigan + Canter:

  Used info from 120 murder cases involving US serial killers.

  Smallest space analysis showed there was spatial consistency in behaviour of killers.

  Location of body sites created a 'centre of gravity'.

  Supports GP to be used to identify offenders.
• Limitation of geographical profiling (insufficient)

  Not sufficient on its own.

  Success of GP relies on the quality of data police may provide.

  Recordings of crime are not always accurate, vary between police forces.

  Estimated 75% of crimes aren't reported to police.

  Alone won't be able to find the offender as there is other important factors such as age of offender, and time of offence.