Forensic Psychology Flashcards
Offender profiling
Offender profiling- a too; exploded by the police to narrow down the list of likely suspects for a crime, it is based on the idea that the characterises of the offender can be deduced from details of the offence and crime scene, involve analysis of the evidence including witness reports in order to generate a hypothesis about the probable characterises of the offender
Top down approach
Templates of organised and disorganised offenders are pre-existing in the mind of the profiler, evidence from the crime scene and other details of the crime are then used to fit the offender into either of the two pre-existing categories
Evaluation of top Down approach
-not useful for all sorts of crimes like robbery
-the system was developed on interview of 36 serial killers in the USA. Sample is too small, relies on self report
-overly simplistic, visionary, mission, hedonistic and power serial killers
Bottom up approach
Date-driven approach involving use of data from crime scene and victim to build a statistical database, the info is analysed to find relationships between crimes. Investigate psychology- one assumption is interpersonal coherence (idea that the offender behaves consistently at the crime scene and in real life), another assumption is significance of time and place. Forensic awareness describes individuals who have made an attempt to cover their tracks, showing that they may have been a subject of police interrogation previously.
Evaluation of bottom up approach
+it is objective, unlike top down which is far more reliant on intuition
+can be applied to wide range of crimes
-the success relies on accurate and detailed record being kept in criminal database
-chemistry students pride a more accurate offender profile than an experienced senior detective
- examples of failure e.g. in 1992, 21 yr old women stabbed 47x and sexually assaulted, in 2008 it was found that Robert was her murder but the ruling claimed him out earlier because he was several inches taller than the profile had claimed he would be
Geographical profiling
Study of spatial behaviour in relation to crime and offenders, focusing on the location of the crime and the evidence of the extent of the criminals local knowledge. Three key principles: least effort, distance decay, centre of gravity hypothesis. Crime mapping and anya,is sfo spatial decision making can reveal whether an offender is a marauder or commuter
Evaluation of geographical profiling
-not useful for financial crimes or crimes of passion where the offenders behaviour is not necessarily linked to a specific location
+a successful use was identification of John DUffy, the railway rapists- he was a marauder
+120 murder cases involving serial killer in the us studied, location of each body disposal was plotted, and a centre of gravity was identified, effective more noticeable for marauders
Historical approach to offending
Italian physician, Lombroso suggested that criminals were ill suited to modern society, he be,imbed that criminals generic throwbacks, a primitive sub-species, who were biologically different from non criminals, they were seen as lacking evolutionary development, their savage and untamed nature means they would find it difficult to adjust to civiliazed society and so turn to crime
Atavistic form
Criminal sub-species could be identified by a set of particular physiological characteristics that were linked to particular types of crime, these were biologically determined atavistic (revision to something ancestral), cranial characteristics include strong prominent jaw, high cheekbones, facial asymmetry
Evaluation of atavistic form
-racism (eugenic philosophy)
-3000 criminals vs 3000 non criminals, no evidence suggesting that the offenders had particular facial characteristics, he did suggest that there was a difference of intelligence
-he did not compare his criminal sample to a non criminal control
-even if criminals have atavistic features it doesn’t mean that it causes offending- poverty
Genetic explanation for offending behaviours
Indicates that future offenders inherit a gene or combination of genes, that disposes them to commit crime, Lange (1930) investigates 13 MZ and 17 dz twins, atleast one of the twins has served time in prison. 10 of the 13 MZ was 2 of 17 in DZ (time in prison), polygenic and candidate genes. MAOA- dopamine and serotonin in the brain- linked to aggressive behaviours and CDH13- substance abuse and attention deficit order. Diathesis stress model- genetics influence criminal behaviour but moderated by the effects of the environmen
Neural explanation of offending behaviours
There may be neutral difference in the brains of criminals vs non criminals, much of the evidence comes from individuals with anti-social personality disorder, associated with reduced emotional response and a lack of empathy. Reduced activity in the pre-frontal cortex of the brain (part of the brain that regulates emotional behaviour), research shows that there is 11% reduction in grey matter in the prefrontal cortex of the people with apd compared to a normal group
Evaluation of genetic and neural explanation
-concordance rates aren’t always 100%, and can be due to shared learning experiences rather than genetics
-brain scan studies show pathology in brains of criminal psychopaths but can not conclude whether they r genetic or signs of early abuse
-the term offending behaviour is vague, some specific forms of crime may be more biological than others, e.g. physical aggression
-Reductionists
-deterministic: a person with genetic vulnerability shouldn’t be he,d accountable
Eysencks theory of criminal personality
Our personality traits are biological in origin and come about through the type of nervous system we inherit from our parents, so all personality types have innate biological basis, offenders have distinctive genetic personality traits, they are high in neuroticism (unstable and unpredictable, due to their inherited nervous system type couldn’t be conditioned so don’t learn from their mistakes), extroversion (thrill seekers and impulsive) , and psychoticism (cold, lack empathy)
Evaluation of eysencks theory of criminal personality
-offenders tend to score higher on psychoticism, but not extraversion and neuroticism when compared to non offenders
-overly simplistic, crime is too varied and you can’t compare bulgary to committing murder
-cultural differences
-hard to measure personality on a scale, and people’s personality changes with whom they are