Offender profiling

Offender profiling

An analytical tool used to help investigators accurately predict and profile the characteristics of unknown criminals

Top-down approach

• American method inveted in 1970s

• Uses pre-established categoies and templates/schemas to narrow down a list of suspects - caterogosin into disorganised or organised based on evidence at crime scene and witness accounts

• Developed from FBI interviews with 36 murderers. Data from crime scene matched to category and then predicts other characteristic

Construting an FBI profile - step by step

1. Data assimilation (crime scenes, post mortems)

2. Crime scene classification

3. Crime reconstruction (hypotheses about sequence of events & behaviors of victim)

4. Profile generation (physical, demograohic, personality)

Disorgansised vs organised

• Pre-meditated vs impulsive / unplanned

• Controlled vs uncontrolled behaviour during crime

• Brings weapons vs improvised random objects

• Evidence destroyed vs left behind at scene

• Targetted victim (specific type) VS random

• Competent (married or co-habit) VS socially inadequate (live alone + single)

• Higher IQ & skilled job VS lower IQ & unemployed

Strengths AO3

• Canter et al - Analysis of 39 crime scene / offender action variables in 100 murder cases from different convicted serial killers. Confirmed FBI’s typology for organised offenders/supported organised category.

• Convenience: The template can be effective and it is quick + intuitive, drawing on the expertise of skilled investigators to identify patterns and likely offender types.

• Application: Top-down approach thought to only work for violent serial crimes, however in 2017 research when applied to burglaries, 85% rise in solved cases in US since introductio

Limitations

• Most killers have multiple contrasting characteristics, don’t fit into one ‘type’. Also, there is no evidence for the ‘disorganised type’.

• However, it is overly simplistic and inflexible, relying on subjective judgments and limited types which may not fit all crimes or offenders, reducing accuracy. (crimes often include elements of both)

• Methodology: Approach is based on interviews with a small number of unusal serial offenders, not randomly selected, all similar characteristics (not representative), no control group and uses non-standardised questions = not scientific

• Self-report is an issue as it can be based on investigator effects as well as the offender manipulating the interview (social desirabilit)

Bottom Up

• British method devloped in 1990 by Canter

• Data-driven approach which gathers info from crime scene evidence to devlop a hypothsis about the offender's harctertics in order to build up a profile.

• No initial schemas or assumptions - slower process

• Interpersonal cohernece: Theory that offender’s criminal activity reflects their daily life (gives clues)

• Forensic awarness: Individuals who have experinced police investigtions before often leave behind less evidence

Geographical profiling

• A method of bottom-up which is based on the principle of spatial consistency - offender's base and future crime scenes can be deduced based on location of previous crimes (operate in familiar areas)

• Canter’s Centre of gravity: Marauders operate close to their home whilst commuters commit their crimes away 

• Heat map from data about distances, times and movements to predict the next crime scene.

Strengths AO3

• Godwin: Found that 85% of offenders he studied lived within the circle encompassing their offenses → suggests many operate in familiar areas/ geographic profiling

• Canter & Heritage: Small space analysis of 66 solved sexual assault cases found consistent pattern of behaviour which supports interpersonal coherence and case linkage

• Canter & Ludrigan: Studied 120 solved murder cases in US and found spatial consistency in the behavior of killers. The body’s disposal site created a centre of gravity pointing to the offender’s home base.

• Application: This approach can be applied to a variety of criminal activity including burglaries and car crimes - also praised for scientific

Limitations

• Relies on database from historical solves cases → reduces use for unsolved crimes and up to 75% of crimes are not reported which makes the data incomplete → may lead to wrongful convictions

• Copson: Survey responded by 184 detectives revealed that although 83% of them found Bottom Up profiling helpful, only 3% of cases accurately identified the offender → approach may be better for narrowing suspects than solely identifying