Forensic psychology revision notes shortened
Offender profiling: The top-down approach
Description:
1. Aims to narrow list of suspects. Scene and other evidence are analysed to generate
hypotheses about probable characteristics of offender (e.g. age, job, background etc.)
2. FBI interviewed 36 sexually-motivated murderers, used this data and characteristics
of their crimes to create two categories (organised and disorganised) based on ways of
working.
3. Organised = plan the crime, targets victim, or may have a ‘type’ of victim, high
degree of control during crime, little evidence left behind, above average IQ, in a
skilled/professional job. Usually married, may even have children.
4. Disorganised = little evidence of planning (spontaneous), crime scene reflects
impulsive nature, e.g. body still at the scene, shows little control, below-average IQ,
may be in unskilled work or unemployed. A history of failed relationships, living
alone, possible history of sexual dysfunction
5. Four main stages in construction of an FBI profile. 1. Data assimilation = review of
evidence 2. Crime scene classification = (dis)organised
6. 3. Crime reconstruction = generation of hypotheses about the behaviour and events 4.
Profile generation = generation of hypotheses about offender (e.g. background,
physical characteristics, etc).
Evaluation:
1. + Research support for an organised category. 100 US serial killings analysed.
Smallest space analysed used to assess the co-occurrence of 39 aspects of the serial
killings. Revealed a subset of behaviours which matched the organised offenders
profile. Has some validity.
2. CP: Most killers have multiple contrasting characteristics. Don’t fit into one ‘type’.
(Godwin).
3. + Can be adapted to other types of crime e.g. burglary. Recent application to burglary
has led to an 85% rise in solved cases in 3 US states. Detection method adds two new
categories interpersonal (knowing the victim, steals something important),
opportunistic (inexperienced young offender). Wider application.
4. - Evidence for top-down profiling was flawed. FBI agents did not select a random or
large sample, didn’t include different kinds of offender. No standard set of questions,
data not comparable. Does not have a sound, scientific basis.
Offender profiling: The bottom-up approach
Description:
1. The profile is ‘data-driven’ and emerges as investigator finds more details. Aim = to
generate a picture of the offenders’ characteristics, routines, and background through
analysis of the evidence.
2. Statistical procedures detect patterns of behaviour that are likely to occur (or coexist)
across crime scenes. Done to develop a statistical ‘database’ which acts as a baseline
, for comparison. Features of a crime can be matched against database to suggest
important details about offender e.g. history, family background, etc.
3. Interpersonal coherence – the way an offender behaves at the scene (including how
they ‘interact’ with victim) may reflect everyday behaviour (e.g. controlling,
apologetic, etc), i.e. their behaviour ‘hangs together’ (has coherence). Might tell
police about how offender relates to women e.g. more generally.
4. Geographical profiling – based on the principle of spatial consistency – that an
offenders operational base and possible future offences are revealed by the
geographical location of their previous crimes Crime mapping = Location of crime
scenes used to infer the likely home or operational base of an offender. Spatial
consistency = restricting their ‘work’ to areas they are familiar with.
5. Marauder = operates close to their home base. Commuter = likely to have travelled
further away from their usual residence.
6. Circle theory = pattern of offending locations likely to form a circle around offender’s
usual residence, this becomes apparent with more offences.
Evaluation:
1. + Support for investigative psychology. 66 sexual assault cases analysed using
smallest space analysis. Several behaviours were identified in most cases. Each
individual displayed a pattern of behaviours, helps establish if multiple offences
committed by same person (‘case linkage’). Supports consistency in behaviour.
2. CP: case linkage depends on the database, and this will only consist of historical
crimes that have been solved. May have been relatively straightforward to link these
crimes together in the first place and solve them. A circular argument. May tell us
little about crimes that have few links between them and therefore remain unsolved.
3. + Evidence also supports geographical profiling. Information gathered from 120 US
murder cases. Smallest space analysis revealed spatial consistency – a centre of
gravity. Offenders leave home base in different directions when dumping a body but
created a circular effect, especially marauders. Supports geographical profiling.
4. – Geographical profiling may not be sufficient on its own. Reporting of crime not
always accurate, 75% of crimes not reported to police. Even if data correct, other
factors e.g. timing, age, and experience of the offender matter. Geographical info
alone may not lead to successful capture of an offender.
Biological explanations: An historical approach
1. Lombroso’s historical approach laid foundations of profiling. Proposed criminals
were ‘genetic throwbacks’ who were biologically different from non-criminals =
‘atavistic form’.
2. Offenders lack evolutionary development – savage and untamed nature meant they
would find it impossible to adjust to civilised society and inevitably turn to crime.
Lombroso saw offending behaviour as an innate tendency, suggesting offender not at
fault. Revolutionary ideas.
3. Offender subtype identified by the physiological ‘markers’, ‘atavistic’ characteristics
= biologically determined.
4. Physical and emotional features. Skull features= a narrow, sloping brow, strong,
prominent jaw, high cheekbones, facial asymmetry. Other features = dark skin,
existence of extra toes, nipples, or fingers. Other aspects = insensitivity to pain, use of
slang, tattoos, and unemployment.
