forensics Flashcards
definition of offender profiling
process of predicting the characteristics of an offender based on information available
features of top-down approach
-starts w big picture and fills in details
-developed using 36 sexually motivated serial killers
-4 stages:
1. data assimilation
2. classification
3. reconstruction
4. profile generation
-organised vs disorganised offenders
eval of top-down approach
-practical app - aids in solving crime
-not generalisable - only applied to sexually motivated serial killers
-reductionist - organised/disorganised
-ethno/androcentric - done in US on men
-temporal validity - alison et al - based on theories of personality being stable for a person’s lifetime
features of bottom-up approach
-starts w small details and builds up big pic
-no initial assumptions made
-uses investigative psychology (smallest space analysis- computer database) and geographical profiling
-uses canter’s circle theory - marauders/commuters
what is geographical profiling
-feature of bottom-up approach
-inferring where an offender is likely to live based on the locations of their crimes
what is investigative psychology
-feature of bottom-up approach
-Uses smallest space analysis computer database to identify patterns in behaviour to see if a series of offences are linked
eval of bottom-up approach
-wider applications - used on more than just sexually motivated serial killers
-Canter and Lundrigan - reviewed 120 murder cases using geo profiling and found offenders invariably lived in centre of crime scenes
-scientific and reliable - uses computer databases
-misleading - Rachel Nickell - wrong person arrested using bottom-up, so can only be used in conjunction w other investigation methods
atavistic form - explanation
-bio explanation of crime
-Lombroso - suggests criminality is inherited and some are ‘born criminal’ as offenders are ‘genetic throwbacks’ or a ‘primitive sub-species’ that cannot conform to rules of modern society
-have physical features eg. large protruding chins, baldness, tattoos, hawk-like noses, hard eyes etc.
atavistic form - Lombroso research
-used over 4000 dead and alive italian criminals
-found 40% had atavistic features
strengths of atavistic form
-research support - sheldon’s body types - male delinquents more likely to be mesomorphs (largest, strongest body type) than male students of similar age. this body type associated w courage, aggression and risk-taking
-beginning of offender profiling - first to take scientific approach so acted as starting point for research
limitations of atavistic form
-low validity - didnt have control group, so characteristics may have just been common in general pop OR traits may be due to poverty, disease, poor diet etc
-scientific racism - traits identified are more prevalent in certain racial groups
-alt explanation - Goring - found criminals to have below average intelligence, so crime may be due to lack of education, rather than biology
-lack of temporal validity - from time when eugenics theories were popular eg. Hitler
bio explanations - neural explanations of crime
-Raine - found individuals w APD had 11% reduction in grey matter in pre-frontal cortex associated w emotional reg and empathy - used PET scans
-Keysers - suggested mirror neurons (responsible for empathy) did not function the same way in individuals w APD - had to be told to feel empathy when watching film of person in pain
bio explanations - genetic explanations of crime
-Christiansen - twin studies - studied 3586 twin pairs from Denmark and found 52% concordance for criminality in MZ and 22% in DZ
-Brunner - MAOA gene - studied 5 men from Netherlands from same family who showed abnormal violent and sexual behaviour - collected urine samples and analysed medical, school and criminal records - MAOA decreases serotonin, dopamine and noradrenaline levels
evaluation of bio explanations
-limitations of twin studies - no 100% concordance and difficult to differentiate between nature and nurture due to shared upbringing
-bio determinism and reductionism - criminals have free will and crime has varied reasons
-case study - Jim Fallon - has brain of serial killer (mutated MAOA gene and reduced prefrontal cortex activity), yet is not criminal due to good upbringing
-crime is social construct so bio explanations are illogical
psychological explanation of crime - eysenck
-Eysenck’s theory of personality
-personality is innate and has a biological basis
-there is a ‘criminal personality’ and these people will score highly on measures of extraversion, neuroticism and psychoticism
-these people are seen as difficult to condition and cold/unfeeling