forensics - offender profiling Flashcards
what is offender profiling?
investigative tool employed by the police when investigating crime to narrow down the potential offenders.
when and who developed the top down approach?
Developed in 1970s, US by the FBI
how was top down approach developed?
Behavioral science unit gathered date from interviews with 36 sexually motivated serial killers.
what is the top down approach also called?
typology
what is the typology approach?
offender profilers will match what is known about offender/crime to pre-existing templates. There classified into either organized or disorganized
what is a disorganised crime?
spontaneous, impulsive, low IQ, unskilled, live alone
what is a organised crime?
planned, particular victim, controlled, ^ IQ, sexually + socially competent
structure of FBI profiling
1) data assimilation
2) crime scene class
3) crime reconstruction
4) profile generation
what are two examples of offender profiling?
the top-down approach
bottom-up approach
what is the aim of the bottom up approach?
generate picture of the offender, likely characteristics, behavior and social background through systematic (empirical) analysis of the crime scenes
what is the difference between top-down and bottum-up
doesnt begin with typologies it is data driven
what does investigative psychology use to asses crime?
statistical analysis and psychological theories
what are two forms of the bottum up approach
investigative psychology and geographical profiling
what is interpersonal coherence?
this is the idea that is central to inveistigative psychology how an offender act with their victim may reflect their behaviour in everyday situations
what is forensic awareness?
it is people who have been in crime before, their behaviour may show how well they are at covering their tracks
what variables are key for investigative psychology?
interpersonal coherence
time and place
forensic awareness
who first proposed geographical profiling?
kim rossmo
what is the assumption in geographical mapping>?
that offender will restrict their crime to areas theyre familiar with and understadning this area will provide a CENTRA OF GRAVITY
where is the offenders base usually?
in the middle area of the centre of gravity
what does the centre of gravity allow?
it allows the researchers to predict where crime will next occur
know their base - it is in the centre of gravity
what is it called when an invesitgator makes a eductaed guess about where a criminal will attack next?
jeoprady surfaces
who produced circle theory?
canter and larkin 1993
what two models does circle theory put forward?
the marauder
the comuter
the marauder behaviour?
operates close to home
the commuter behaviour?
crime far from home
research support for geographical profiling
canter - collated info for 120 murder cases in the US. a centre of gravity was found for most and the offdenrs base was in the middle. This suports laim that spatial info us key for determing base of offender
evaluate bottom up approach
+ canters research into investigative psych
- Copson found in 48 police it only led to correct identification in 3% of criminals
+ canters research into geographical profiling
+ used on a wide range of cases - bulgary etc better than top-down
what did canter find for the top-down approach?
canter analysed data from 100 murderers to see if they had any of the 39 charcetoristics associated with organised and non-organized criminals
found evidence of an organised criminal but not a disorganised one
what is the general method of offender profiling?
scrutiny of the crime scene
analysis of evidence (EWT)
what does offender profiling mean the investigator can hypothesize?
can hypothosise traits of offender such as age, occupation etc
what will offender profillers using the typology approach do?
They will match factors in the crime scene to the pre-existing in the templates found by the FBI
who formulated geographical profiling?
rossmo
what is data assimilation?
reviewing the evidence
what is crime scene classification?
organised vs disorganised
what is crime reconstruction?
prediction about the events of the crime
what is profile regeneration?
prediction about traits of the offender
what is the latin for having your own way for doing something?
modus operandi
evaluate top-down approach?
-> Canter = 100 criminals, 39 traits found evidence of organized crime but couldn’t for non-organized
–> only fitting to macabre crimes that could leave evidence behind. Not suitable for crimes like theft which do not tend to reveal much about the offender
–> classification is too simple - more likely to have traits from both types so that means you cant make predictions
–‘>original bases is not generalizable was based on 36 criminals (25 were serial killers)
–> outdated models of personality - old fashioned and static- criminal behavior is not always disposition- situation can change crime
investigative psychology A01
- uses statistics and psychological theories to analyse crime scene evidence
- establish likely patterns of behaviour
- develop a database which can be used to compare offences to
- details of offence can be matched to the dtabase
- this will reveal details of the crime
- and you can also determine if many offences are linked
- interpersonal coherence
- time and place
- forensic awareness
what details may the database from investigative psychology reveal
their history or family and background
what is geographical profiling?
- put forwar by rossomo
- uses the location of crime to make inferences about the home or base of the offender (crime mapping)
- sometimes uses psychological theories to also make inferences about how theyre thinking
what does a criminals spatial decisions allow the profiler to know?
- wether it was planned
- age
- mode of transport
- job
what was canters research into geographical profiling
analysed a serial murder case of 120 murders and found that their base was in the middle
what was canters research into investigative psych?
canter used a statistical tool on 66 criminals that correlated behaviors between them and found behavior associated with crimes and the patterns they develop in. this shows the usefulness of stats on offender profiling
