Forensics - Offender profiling

Question 1

Offender profiling

Answer 1

Investigative techniques to narrow down a suspect list by identifying major characteristics from the crime scene

Question 2

Top-down approach

Answer 2

Uses general classification to make judgements about the offender based on the profiler’s intuition & experiences (used by FBI)

Question 3

Organised offenders

Answer 3

• Planned
• Victims are targeted
• Little evidence left
• Intelligent
• Typically married w/kids

Post offence: returns to the scene, follows the investigation via news, volunteers information
Interviews: direct strategies

Question 4

Disorganised offender

Answer 4

• Unplanned
• Spontaneous offences/victims
• Evidence & body left at crime scene
• Unskilled w/low intelligence
• Loners

Post offence: returns to the scene to relive, keep newspaper cuttings of events & a diary
Interviews: empathise with offender, indirectly introduce evidence

Question 5

4 stages of constructing profile (T-D approach)

Answer 5

1. Data assimilation (review evidence, photos, medical examiner report, victim background)
2. Crime scene classification (organised or disorganised)
3. Crime reconstruction (hypotheses about sequence of events & behaviour)
4. Profile generation (hypotheses related to the offender i.e. physical characteristics, demographic)

Question 6

Strengths of T-D profiling

Answer 6

+ Supporting evidence:
1. Canter et al - 100 cases by serial killers found a subset of features that matched the FBI’s typology
2. Maketa - application to burglaries found 85% rise in solved cases & added two new categories (interpersonal & opportunistic)
3. McCrary & Grant - used profiling on a man responsible for murdering prostitutes to find close match

+ Behavioural consistency (create links between offences based on crime scene similarity)

Question 7

Limitations of T-D profiling

Answer 7

• Contrasting characteristics (Godwin - difficulty classifying as could have high IQ but leave evidence)
• Change in modus operandi (offenders become more forensically aware & organised -> hard to link their earlier offences to later ones)
• Methodological issues (Canter et al - poor sample used for creation of categories [only 36 & only sexual offenders], was not standardised)
• Gives little information about offender (Mischel - driven by the situation -> does not reflect how they are in everyday life)

Question 8

Bottom-up approach

Answer 8

Collects details/evidence of the crime scene & statistically analyses the data using jeopardy surface to generate predictions/hypotheses (British) [Data-Driven]

Question 9

Canter’s 5 factor model (B-U approach)

Answer 9

1! Interpersonal coherence (interactional style with victim reflects daily life)
2! Time & place significance (chosen to commit crime there so must hold some importance to offender i.e. comfortabilities & schemas)

3. Criminal characteristics (how crime was committed reflects personality)
4. Criminal career (following same offender sees crimes changing over experience)
5. Forensic awareness (how knowledgeable the offender is of the CJS & forensics)

Question 10

Assumptions of geographical profiling (B-U)

Answer 10

• Crimes are not random
  + Least effort principle (choose place closest to them out of all attractive locations)
  + Distance decay (number of crimes reduce further away they are to their home base until their confidence grows [buffer zone around home base - decrease recognition])
  + Circle center of gravity (circle can be drawn from furthest points out to encompass all crimes & the home base)

Question 11

Commuter & Marauder theory (B-U)

Answer 11

A commuter style offender travels away from their home base and usual places
A marauder style offender remains closer to their home base

Question 12

Strengths of B-U profiling

Answer 12

+ Spatial consistency (Lundrigan & Canter - location of body disposals created a circle of gravity & was noticeable in 120 marauder cases)
+ Useful (Copson - 83% of police forces judged it as helpful -> validity)
+ Applicable to wider range of crimes (uses locations -> generalisable)
+ Scientific (objective & measurable, statistical analysis & psychological theories)

Question 13

Limitations of B-U profiling

Answer 13

• Reliant on data quality (75% crimes are not reported to police & other factors are equally as important as location i.e. timing of offence & age of offender)
• Issues with validity (Koesis et al - chemistry students more accurate at profiling than experienced professionals)
• [HOWEVER] Useful (Copson - 3% lead to accurate identifications)