Forensics - Offender Profiling Flashcards
Offender profiling
Used to narrow down list of suspects from analysing the crime.
Top-down approach
General classification of a crime scene.
Make judgements about likely offenders.
What does the top-down approach rely on?
Experience of the profiler
When is top-down used?
In extreme cases
E.g. murder and rape
Ressler, Burgess & Douglas
Interview
36 sexually motivated serial killers
Data used to identify typologies
What do interviewers have to do when interviewing offenders?
Leave psychological baggage outside.
Done to eliminate bias
Crime scene of organised
Victim targeted
Restraints used to control
Aggression
Body moved from scene
Evidence largely absent
Characteristics of organised
Above average IQ
Socially & sexually competent
Limited change in behaviour after crime
Follows case on news
Crime scene of disorganised
Spontaneous
Victim known to offender
Little control
Evidence present
Body present
Characteristics of disorganised
Less than avg IQ
Lives near scene
Socially & sexually incompetent
Major behaviour change
Returns to scene
Keeps ‘trophies’ - Domino killer
Problem of top-down
Too subjective
No clear boundary into disorganised or organised
What are the 4 stages for top-down?
Data assimilation
Crime scene classification
Crime scene reconstruction
Profile generation
What is data assimilation?
Reviewing all evidence
E.g. photos & background details of victim
What is crime scene classification?
Classify the scene as disorganised or organised
What is crime scene reconstruction?
Hypothesis about the events of the crime
What is profile generation?
Construct a sketch of the offender using characteristics
What is the bottom-up approach?
Work from evidence collected to hypothesise likely characteristics & motivations
Investigative psychology
Apply statistical procedures & psych theory to analyse crime scene
Geographical profiling
Info about location of crime to make inferences about the likely operational base of offender
5 factor model for interpreting crime scenes
interpersonal coherence
time and place significance
Criminal characteristics
Criminal career
Forensic awareness
What is interpersonal coherence?
Offenders interactions with victim is same as with other people in their life
What is time and place significance?
Location chosen by offender is significant to them.
More likely to feel comfortable somewhere familiar to them
What are the two types of geographical profiling?
Commuters
Marauders
What are commuters?
Travel for the crime
What are marauders?
Stick to own area for crime
What are the 3 assumptions of geographical profiling?
Least effort principle
Distance decay
Circle of gravity theory
What is the least effort principle?
Offender will choose the criminal,y attractive area that is closest to them
What is distance decay?
Crimes will reduce further away from base until they grow confident
What is circle of gravity?
If a circle is drawn around the furthest crime scenes, the offender will likely live in that circle
