offender profiling

offender profiling

• based on the idea that characteristics of an offender can be deduced from characteristics of offence and details of crime scene.

• main aim is to narrow field of enquiry and list of likely suspects.

• compiling of profile will usually involves:

  1. careful scrutiny of crime scene and analysis of evidence (including witness reports).

  2. generate hypotheses about probable characteristics of offender - age, background, occupation, etc.

top-down approach/top-down typology

• originated in USA as a result of work carried out by the FBI in 1970s.

• FBI’s Behavioural Science Unit drew upon data gathered from in-depth interviews with 36 sexually motivated serial killers including Ted Bundy and Charles Manson.

• profilers who use this method will match what is known about the crime and offender to a pre-existing template that FBI developed using data they gathered from interviews.

• murderers or rapists are classified as organised or disorganised on basis of the evidence, and this informs the subsequent police investigation.

organised offender

• shows evidence of having planned the crime in advance.

• victim is deliberately targeted and will often reflect that the killer or rapist has a 'type'.

• they maintain a high level of control during the crime and may operate with almost detached surgical precision.

• there is little evidence or clues left behind at the scene.

• they tend to be of above-average intelligence, in a skilled, professional occupation and are socially and sexually competent.

• they are usually married and may have children.

disorganised offender

• shows little evidence of planning - offence may have been a spontaneous spur of the moment act.

• crime scene tends to reflect impulsive nature of attack - the body is usually still at the scene and appears that offender had very little control.

• tend to have a lower than average IQ, be in unskilled work or unemployed, and often have a history of sexual dysfunction and failed relationships.

• tend to live alone and often relatively close to where offence took place.

constructing a profile

1. data assimilation - info gathered from crime scene and other sources about exactly what happened. They will look at photos of scene, forensic evidence, police reports, etc.

2. crime scene classification - a decision is made regarding whether criminal appears to have planned act (organised) or acted hastily and unplanned (disorganised).

3. crime reconstructor - hypotheses are generated about what probably happened during the crime scene, e.g. victim behaviour and sequence of events.

4. profile generation - rough ‘sketch’ of criminal is developed including: social groups, appearance and likely behavioural traits.

top-down weakness - origin

• unscientific development.

• developed using interviews with 36 male sexually motivated murderers in USA.

• sample too small and unrepresentative to base typology system on.

• classification system was constructed based on self-report data from convicted killers who may lie or exaggerate in interviews.

• therefore data approach is based on lacks validity.

top-down weakness - range

• limited range of crimes that profile can be applied to.

• sample is based on males convicted of violent, sexual crimes → can only be used in violent crimes like murder.

• more common offences, e.g. burglary, don’t apply to top-down profiling as resulting crime reveals little about offender.

• limited approach for identifying all criminals and crimes.

top-down weakness - success/usefulness

• idea of a criminal being either organised OR disorganised is too simplistic.

• Canter (2004):

  • analysed 100 serial killers in USA who were classified as organised or disorganised.

  • found there was no distinction between the two and concluded that all these crimes will have an organised and disorganised element to them.

  • suggests it is better to study individual personality differences between offenders than organised and disorganised elements to crimes.

• reduces support as having just two types is too restrictive → affects accuracy of profiling system.

bottom-up approach

• builds a picture of potential criminal from facts and figures collected from previous crimes of the same type.

• removes the intuition element of profiling → a data driven approach.

• more grounded in psychological theory → investigative psychology.

investigative psychology

• term used to describe a fine tuned approach by David Canter in UK.

• key underlying assumptions of crime, specifically what occurs between victim and offender:

  • interpersonal coherence - way an offender behaves at the scene, e.g. how they interact with victim, may reflect behaviour in everyday situations → e.g. an aggressive person is more likely to commit an aggressive crime.

  • significance of time and place - similar to time and location factors in top-down where positioning/timing gives clues as to where perpetrator might live or work, however uses statistical techniques.

  • forensic awareness - individuals who have been subject of police interrogation before - behaviour may denote how mindful they are of covering their tracks.

smallest space analysis

• a computer program that identifies correlations across patterns of behaviour.

• establishes patterns of behaviour likely to occur or co-occur across crime scenes → helps develop a statistical 'database' which acts as a baseline for comparison.

• specific details of offence or related offences can be matched against database to reveal important details, e.g. personal history, family background, etc.

• may determine whether a series of offences are linked - may have been committed by the same person.

geographic profiling

• used by bottom-up approach.

• Canter proposed that people don’t just reveal themselves through crimes they commit but also through locations they choose.

• assumption is that serial offenders will restrict crimes to geographical areas they are familiar with → understanding spatial pattern of their behaviour provides investigators with a 'centre of gravity' likely to include offender's base (often in the middle of spatial pattern).

circle theory

• geographical profiling may help investigators make educated guesses about where offender is likely to strike next - 'jeopardy surface'.

• Canter and Larkin (1993) - proposed two models of offender behaviour:

  • marauder - offenders home is within geographical area where crimes are committed.

  • commuter - offender travels to another geographical area (often familiar) and commits crime within a define space where a circle can be drawn around.

• pattern of offending is likely to form a circle around usual residence, and this becomes more apparent the more offences there are.

• spatial decision-making can offer investigative team insight into nature of offence → organised or disorganised, important factors about offender, e.g. mental maps, mode of transport, employment status, approximate age, etc.

• mental maps - people’s internal representations of external world that’s unique to each individual.

bottom-up strength - origin

• scientific development.

• profiles are data driven and use psychological theory and statistical analysis, e.g. geographical profiling.

• supporting research: Canter and Goodwin (1997):

  • found that 85% of offenders lived within circle encompassing offenses.

• therefore more objective way of developing profile → don’t have to rely on intuition.

bottom-up strength and weakness - range

• can be applied to wide range of offences.

• smallest space analysis and the principle of spatial consistency can be used in investigation of both smaller crimes and serious offences.

• however → Koscis (1997):

  • found that only 50% of burglars lived in circle defined by offences.

• suggests that although applies to a wide variety of offences, some crimes like theft may be harder to profile successfully.

bottom-up strength and weakness - success/usefulness

• psychological profiles based on this approach assisted police in catching offenders on numerous high-profile cases, e.g. John Duffy.

• Copson (1995):

  • surveyed detectives who had worked with offender profiling.

  • found that advice given in the profiling was useful in 83% cases where it was used.

  • however → only helped catch the offender in 3% of cases.

• one problem seems to come from lack of consistency in British approach: multiple people in UK providing psychological profiles for police with different backgrounds in psychology and psychiatry → each uses own approach with success, but not one specific way of profiling.