Forensics

A level psychology ~ forensics

Offender profiling

Narrowing down the number of potential suspects rather than naming one person

top down approach

general classification of the crime scene to drill down to make judgements about potential offenders

4 stages of profile construction

1. Data assimilation

2. Crime scene reclassification

3. Crime reconstruction

4. Profile reconstruction

data assimilation

Review evidence

Crime scene classification

Classify criminal as organised or disorganised

Crime reconstruction

Hypothesise sequence of events, behaviour and victim

Profile generation

Hypothesise offender characteristics, traits, demographic

Only applies..

only applies to certain crimes, like serial killers, where they can reveal information about the suspect, doesn’t apply in cases like burgalary

Sample bias

Based on interviews with s3x offenders and serial killers, cannot be generalised to ordinary criminals

Unreliable

uses structured interviews, questions are unpredictable and changing; wont be the same for all criminals

Evaluation of top down approach

1. Jarvis et al: May not identify criminal, but will give hints and clues

2. Interviews with manipulators may lack validity

3. Snooker at al; unscientific as its just predictions of behavior

4. Alison et al; naive and outdated, stereotyping

5. Douglas et al; mixed offender

Bottom up approach

Data is collected from crime scene and analysed using statistical techniques to generate predictions

David canter

proposed that profiling should be based on psychological theory and research; did case on railway rapist

3 main features

1. Interpersonal coherence

2. Forensic awareness

3. Smallest space analysis

Interpersonal coherence

people are consistent in their behaviour and so there will be links in their behaviour and crime

Forensic awareness

certain behaviours may reveal an awareness of particular police techniques. David et al found grapists who conceal fingerprints had been caught for buglary

Smallest space analysis

Statistical technique data about crime scenes and offender characteristics are correlated so common connections can be identified

Canter et al - smallest space analysis

analysed 48 crime scenes and offender characteristics and identified 3 underlying themes

1. Instrumental opportunistic: murder is to accomplish a goal, choose an easy opportunity

2. Instrumental cognitive: more planned due to a fear of detection

3. Expressive impulsive: uncontrolled due to strong emotions

Geographic profiling - Kim Rosso

Using the location of crime scene, you can infer where the offender lives. (Crime mapping)

• Criminal will restrict crimes to familiar places, so spacial patterns of behaviour can provide a centre of gravity where theyre likely to offend

Canter - circle theory

mauruder: close proximity to home base

Commuter: travels a distance away from home base

Criminal geographical targetting - kim rosso

Computer system; proposes 3 dimensional map displaying spacial data related to time, distance and movement to/from crime scenes

Evaluation good bottom up approach

1. Scientific, uses scientific methods such as computer analysis, however, doesn’t tell us about patterns of behaviour

2. RS for usefulness; copson; 75% found it useful, 3% said it helped to identify attacker

3. Canter et al; 91% of offenders classified as maurders, not helpful

4. Police thought geographical profiling was not effective ~ rossmo; can’t distinguish between multiple offenders in the same area, limited to spacial behavior

5. Can’t reliably identify offender, but can narrow down possibilities, racheal nickel; wrong murderer identified, but was ruled our due to height

Biological explanation of offending

atavism

Genetic

Neural

Cesare lombrosso

Suggests criminals were genetic throwbacks and were biologically different

Atavism

An evolutionary throwback, traits reappearing which had disappeared from generations before

Cesare lombrosso’s study

Investigated facial features of Italian criminals, Alive and dead, and found 40% had atavism characteristics who lacked evolutionary development

Criminals characteristics

Prolonged jaw, cheekbones, big forehead

Murderers characteristics

Bloodshot eyes, long eyes

Three types of criminals ~ lombrosso

1. Born criminals

2. Insane criminals

3. Criminaloids (circumstances)

Evaluation of atavism

1. Scientific racism

2. Didn’t compare his study with a control group

3. Features could be influenced by diet

4. Goring ~ found contradictory evidence of atavism not being a thing

5. Lombrosso created criminal profiling

Genetic explanations

Some genes predispose individuals to criminal behaviour

Raine: reviewed research on the delinquent behaviour of twins and found a 52% concordance rate for mz, and 21% concordance for dz