forensic psych Flashcards
(137 cards)
what is the american profilling system
top-down approach
what does the top-down approach mean
means the profillers start with pre-established typology and work down in order to assign offenders to categorise based on evidence from the crime scene
who develpoed the top-down approach and when
the FBI’s behavioural science unit in the 1970’s
how was the top down approach developed
in depth iterviews with 36 sexually motivated serial killers
what are the two categoires in top-down
- organised
- disorganised
describe the organised catagory
general approach, weapons, evidence, victim, offender
general approach - planned and controlled
weapons - brought to scene and taken away
evidence - destroyed or removed
victim - attempts to control (eg restraints), may be carefully chosen (fits a ‘type’)
offender - unknown to victim, socially/sexually contempt, living with partner, above average intelligence, angry/depressed
describe the disorganised catagory
general approach, weapons, evidence, victim, offender
general approach - unplanned and chaotic
weapons - improvised, left at scene
evidence - left at scene, no attempt to hide/destroy evidence
victim - little attempt to control, randomly chosen (wrong place, wrong time)
offender - possibly known to victim, socially/sexually inept, living alone, below average intelligence, anxious/psychotic
what is the process of constructing an FBI profile
- data assimilation (looks at evidence)
- crime scene classified (into 1 of 2 types)
- crime reconstruction (of sequence of events, behaviour of offender+victim)
- profile generation, related to likely offender (eg demographic background, physical characteristic, behaviours)
opposing evidnece to top down
Pinizzotto and Finkel (1990)
* compared five groups on their ability to write profiles of a solved murder case
* groups were: expert profilers, detectives with profiling expereince, detectives without profilling experince, clinical psychologists and undergrads
* detectives without profilling experince were significantly more accuarate in predicting characteristics of the murderer than any group
what does Pinizzotto and Finkel’s evidence suggest about top down approach
- not effective
- waste of time and money training people in top down
limitation of top down
development
- based on static and outdated models of personality
- assumes offenders have behaviours+motivations that remain consistent consistent across situations – however critics have argued that personality is more dynamic and affected by external factors
ANOTHER LIMITATION - developed by interview of 36 american killers
limitation of top down
applicability
- only applied to certain crimes eg serial murder and rape
- especially if they involve practices such as sadistic torture, dissection of the body and acting out fantasies - these offences are rare
- more common offences such as burgulary dont lend themselves to top-down because the crime scenes reveal very little about the offender
limitation of top down
simplistic
- classification of organised and disorganised is too simplistic
- many characteristocs of the types aren’t mutally exculsive and instead mnay crime scenes show a combination of characteristics
Holmes (1998) suggests there are 4 types of serial killer: visionary, mission, hedonistic and power/control - limitation because questions validity of top-down approach and the use of two categories for classification
what is britains profiling systen
bottom=up approach
what techniques are used in bottom-up
- investigative psych
- geographic profiling
what is investigative psych
investigative psychology is the use of scientific psychology and psychological theory to solve crimes and identify criminals.
two aspecvts in investigative psych
1.** interpersonal coherence**- his means that the way a criminal behaves when they are committing a crime will be consistent with how they behave in everyday life.
2. statistical analysis- identify common themes and patterns of behaviour across several crime scenes, Statistical data can also be used to provide information about the offender’s location through geographical profiling.
what is geographical profiling
use of statistical analysis to make inferences about the offender’s geographical location.
what is the circle hypothesis in regards to geographical profilling
says that serial offenders carry out their crimes within a geographical circle. The circle hypothesis also predicts that the offender’s home will be within this circle.
what are the two geographical models for offending locations
- the marauder
- the commuter
where does the marauder commit crime
commits crimes within a criminal range from their own home
where does the commuter commit crime
Travels away from their own home to an area and then commits crimes within a criminal range of that area
strengths of bottom up approach
- supporting evidence
- wider applications
- more scientific
supporting evidence for bottom up
investigative psych
David Canter used his bottom-up profiling methods to develop a profile of the ‘Railway Rapist’ – responsible for several rapes and murders of women near railway stations in south-east England in the 1980s. Canter developed the profile of a man in his mid-late 20s, with a criminal record, working in a semi-skilled job, who had a poor relationship with women, knowledge of the railways, and lived near the crime scenes. This profile turned out to closely match the details of the offender, John Duffy, who was found guilty of these crimes.