Forensics Flashcards
What is the aim of top-down profiling?
Narrow the field of enquiry and list of likely suspects
How was top down profiling developed?
Hunt for the mad bomber who evaded capture of 16 years in the 40s and 50s
James Brussel drew an incredibly detailed picure which was accurate
What did James Brussel do?
Drew an incredibly detailed picture of the mad bomber, claiming he was an unmarried man, wearing a double-breasted suit
What is the top-down approach based on>
interviews with 36 of convicted sexual killers, including Ted Bundy and John Wayne Gacy
How does top down profiling sort information?
Organised and disorganised crime
Meketa study - top down profiling
looked at robberies
85% increase in solving crime using top-down approach
What are weaknesses of top-down profiling?
Not generalisable
Homology problem
Narrow field of offenders - ignoring possible suspects
Who developed bottom up profiling?
David Canter
What is the aim of bottom up profiling?
Generate a profule of the offender by looking at available evidence
Interpersonal Coherence
Behaviour in crimes reflects behaviour in real life
Forensic awareness
How much the offender has attempted to cover their tracks - indicates whether they have been questioned about crime in the past
What are the 2 ways of profiling in bottom up profiling?
Investigative Psychology
Geographic profiling
What are the two types of offenders in geographic profiling?
The Marauder
Then commuter
What is the Marauder?
Operates in close proximity to their base
The commuter
Travels a distance from their base
Canter and Heritage - SA
Found that when looking at sexual assault, the nature of offence was correlated with particular types of behaviour
This suggests that statistical techniques can be useful in identifying behaviour oatterns, supporting invstigative psychology
Lundrigan and Cantor
120 murder case involving serial killers, they disposed of bodies in various locations, forming a ‘centre of gravity’
Their base was located in the middle of this
Why are bottom up appraoches argued to be more scientific than top down?
Just the available evidence are used to create a profile, rather than attempting to fit offenders to pre-existing templates
Stages if the bottom up approach
- analysis of crime scene evidenc
- psychological theory and statistical analysis
- Creation of hypotheses of the probable characteristics of the offender
Railway Rapist
1975-86
23 women raped around London railway stations
Who was Lombroso?
The father of criminology
What did Lombroso suggest about criminals?
Criminals are genetic throwbacks, a primitive species who are biologically different to non-criminals
Savage, untamed - impossible to adjust to the demands of civilised society so turn to crime
How did Lombroso view offending behaviour?
Natural tendency, rooted in genes
Offending is innate, so criminals could not be blamed for their actions
What did Lombroso study?
The facial and cranial features of:
383 dead convicts
3839 living convicts
Atavistic form
Physical markers of the head and face that make criminals different from the rest of us
Physical markers are rooted in our biology
What % of criminals had atavistic features
40%
Example of atavistic features
Skull
- narrow sloping strong brow, strong jaw, high cheekbones, facial asymetry
Extra toes, nipples or fingers
Left handed
Insensitivity to pain
Atavistic features of murderers
Bloodshot eyes, curly hair, long ears
Atavistic features of sexual criminals
Glinting eyes, swollen fleshy lips
Atavistic features of fraudsters
Thin lips
What was believed to be the cause of offedning behaviour prior to Lombroso?
Demonic possession
Goring - Lombroso opposing evidence
3000 offenders vs 3000 non-offenders
Concluded that there is no evidence that offenders are a distinct group with abnormal facial or cranial features
Though he did conclude that those who commit cime have lower intelligence
What 2 genes are linked to violent and criminal behaviour?
MAOA
CDH-13
MAOA gene
regulates serotonin in the brain
low levels of serotonin are implicated in impulsive behaviour
CDH-13 gene
substance abuse
ADHD
How were 2 genes linked to criminal and violent behaviour?
2015, Finland
800 violent criminals
5-10% of violent crime in Finland can be attributed to these genes
Christiansen - supporting evidence for genetic explanation of offending behaviour - twin study
3500 pairs of twins in Denmark
Concordance rates of offending behaviour
MZ - 35%
DZ - 13%
Crowe - Supporting evidence for the genetic explanation of offending
Adopted children whose biological mother had a criminal record
50% chance of having a criminal record by 18
Adopted children whose mum did not have a criminal record
5% risk of developing a criminal record by 18
Suomi - genetic explanation
Monkeys with MAOA gene
A - left with siblings to fend for themselves
More aggressive
B - raised with mum
Not aggressive
Reductionist vs holism - genetic explanation of offending
1/3 of men have the MAOA gene, however not all of these men are committing crime
Characteristics of ASPD
Risk taking
Dangerous / illegal actions
irresponsible
Lack of remorse
Impulsivity
Boredom from routine
Role of prefrontal cortex
Regulates emotional behaviour
What have brain scan shown about the pre-frontal cortex in relation to offending?
Violent criminals have a lowered activity level om the [re-frontal cortex compared to a non-offender
Raine - ASPD
Many brain imaging studies suggests people with ASPD have:
reduced activity in the pre-frontal cortex
11% reduction of grey matter in the pre-frontal cortex
Kandel & Freed - antisocial behaviour
Reviewed evidence of frontal lobe damage and antisocial behaviour
Found that people with this damage tend to show more impulsive behaviour and emotional instability
Farrington - ASPD
Studied a group of men with high ASPD scores - all experienced risk factors in childhood
Early childhood experiences vs born with neural differences?
Mirror neurons
Monkey sees action
Monkey does action
Keysers - ASPD - mirror neurons
Showed offenders a film of someone in pain
Only when they asked them to sympathise did they see their empathy reaction activate - mirror neurons
Suggests that those with ASPD have a neural switch controlling empathy
What 2 measures did Eysenck propose could measure personality
Extraversion, Introversion (E score)
Neuroticism, Stability (N score)
What is the biological basis of Eysencks theory of CP?
Personality traits are biological in origin and arise from the type of nervous system inherited
All personality traits have an innate, biological basis
Biological basis of extraverts
Underactive nervous system - ARAS, cortical arousal
seek excitement
Do not condition easily
Biological basis of a neurotic individual
Ineffective autonomic nervous system, constant state of fight or flight
general instability means their behaviour is difficult to predict
Nervous, over anxious
The Criminal Personality
Neurotic, Extravert
Score highly in terms of psychoticism
Cold, emotional, prone to aggression
Measuring the CP
EPI
E + N score
Later scale included psychoticism
How is socialisation linked with the CP?
Socialisation is where children are taught to delay gratification to become more socially orientated
Those with high E + N scores have nervous systems which made them difficult to condition so they would not learn easily to respond to antisocial impulses with anxiety
Supporting evidence of CP - Farrington
2070 male prisoners, European, non-violent
2422 male controls
age 16-69
Prisoners scored higher than controls on psychoticism, extraversion and neuroticism
Farrington - CP
Offenders tend to score high on P, but not on E + N
little difference in EEG measures between extraverts and introverts, causing doubt over the biological basis
Not all offenders have thde CP
Barot - cultural bias CP
Hispanic + Afro-Americam offenders
max security prison in NYC
6 groups based on criminal history and nature of offence
Criminals less extravert than non-criminal group
Bartol + Holanchock - barot comment CP
Suggested criminals were less extravert because they were of a different culture to that of Eysenck’s sample
Questions the generalisability of the CP
EEG
Measure of cortical arousal