Forensics Flashcards
offender profiling
a behavioural and analytical tool intended to help investigators accurately predict + profile characteristics of unknown criminals. narrow field of enquired + likely suspects. from intense scrutiny of crime scene + evidence
top down approach
From US, carried out by FBI in 1970s. FBI - data gathered from in depth interview w 36 sexually motivated serial killers (ted bundy). match what they know bout crime + offender and compare/match to pre existing template that FBI developed. criminals (specifically rapists/criminals) can be classified as organised or disorganised from evidence
constructing FBI profile
- Data assimilation (reviewing evidence)
- Crime scene classification (organised/disorganised)
- Crime reconstruction (hypotheses of sequence of events ect.)
- Profile generation (hypotheses about offender)
organised criminal features
- planned + controlled so little evidence left (may operate w almost detached surgical predictions and victim deliberately targeted)
- employed (skilled)
- average/high intelligence
- socially + sexually competent
- leads orderly life + commits crime after an event ( may be married w kids)
disorganised criminal features
- commits crime in act of passion (spontaneous - victim dead usually = no control)
- no evidence of pre planning
- below average intelligence
- poor work history
- socially incompetent
- dysfunctional/failed relationships
- lives close to where offence took place + live alone
Top down approach evaluation - limited application
P - Top down profiling applies to particular crimes
E - best suited to crime scenes reveal important details bout suspect like rape, arson + cult killings
E - method of profiling doesn’t help when crimes more common like burgarly, crime scenes reveal little info bout offender
I - reduces ability for profiling method to be used to identify criminals
Top down approach evaluation -
P - too simplistic
E - behaviours describe organised + disorganised types of offenders aren’t mutually exclusive. eg crime scene can have combination of organised + disorganised characteristics
E - suggest top down profiling may be not be valid way to categorise offenders
I - led to other researchers to propose more detailed typological models like holmes’s who said that there were 4 types of criminals
Top down approach evaluation - behav not same
P - based i ideas that people’s behav to be main same across situations + contexts
E - eg personality drives behav + isn’t impacted by external factors. Several critics have argued this is incorrect + behav is driven by aspects other than personality which r changeable
E - eg some criminals may be affected by certain situations than others + therefore some criminals may commit crime where others wouldn’t
I - reduces validity of top down profiling as it might not be possible to predict offenders next move
bottom up approach
largely developed in uk + more scientific and empirical. generate a pic of the offender (characteristic, routine behav + social background). thro systematic analysis of evidence at crime scene
difference between top and bottom approach
bottom approach :
- doesn’t begin w fixed typologies
- profiles r data driven
- profiles emerge as investigation looks at details
investigate psychology
matches details from crime scene w statistical analysis of typical offender behav patterns based on psychological theory. applies statistical procedures w psychological theory to analysis of crime scene evidence to develop a statically database which can acts as a baseline for comparison. specific details of offences can then be matched against database to relate info bout offender
investigate psychology - eg
railway rapist
- duffy assaulted 24 women + killed 3
- Canger interest in geographic deaths + evidence and combines this w similar attacks
investigate psychology - 5 features
- forensic awareness
- time and place
- criminal career
- interpersonal coherence
- criminal characteristics
forensic awareness
describes indiv who have been subject of police interrogation. useful for understanding lifestyle of criminal
time and place
behav shown in committing crime is behav they would show in their normal lives. can also show where they may be living
criminal career
if they leave little physical evidence then they may ages committed a crime before
interpersonal coherence
how offender behaves toward victim. there’s a consistency between way offenders interact w victims + others in their everyday lives - this helps police by putting offenders into a category
criminal characteristics
characteristics bout offender can help to classify them, which helps police investigation - looks at how experienced they r + what they might do next
geographical profiling
based on principle of spatial consistency. offenders operational base + possible future offences r revealed by geographical location of their previous crimes. uses george pics info to find crime pattern. can make inferences bout likely home or operational base + can tell bout perpetrators familiarity w area (models of offender behav). serial offenders will restrict crimes to geographical areas they r familiar w.
‘centre of gravity’ - offenders base.
‘jeopardy surface’ - where they may strike next
canter’s circle theory
commuter - criminals won’t likely to have travelled away from their usually residence
marauder - criminals who operate in close proximity to their home base
circle will likely form around their usual residence + this becomes more apparent the
more offences there r. can give insight into nature of offence ( planned/ opportunistic) + info bout offender
bottom up approach evaluation - support
P - evidence to support use of statistical analysis in investigative psychology.
E - Canter and Heritage (1990) conducted content analysis of 66 sexual assault cases. A computer program used to identify correlations across patterns of behav. E - Several common characteristics were identified. supports usefulness of investigative psychology as statistical techniques can be applied.
I - can lead to understanding of how an offender’s behav may change or whether 2 + offences were made by same offender.
bottom up approach evaluation - support for geographical profiling
P - evidence to support use of geographical profiling in identifying offenders.
E - Lundrigan and Canter (2001) collected information from 120 murder cases involving serial killers in the US. The location of each body disposal site was in a different direction from previous sites creating a ‘centre of gravity.
E - supports Canter’s claim spatial information is key factor in determining the base of offender.
I - because offenders base was also found in centre pattern meaning offenders could be tracked due to geographical profile made.
bottom up approach evaluation - failures
P - had some failures + studies examining effectiveness of top-down approach has got mixed results.
E - Copson (1995) surveyed 48 police forces and found that the advice provided by the profiler was judged to be ‘useful in 83% of cases.
E - shows although it can be effective, some profiles can cause police to incorrectly identify offenders.
I - impact of this is that some offenders may never be apprehended or innocent people resembling police profiles may be arrested instead.
atavistic approach
biological approach to offending that s criminal activity r genetic throwbacks ill-suited to conformity to society’s standards.
atavistic
suggested criminal sub-type could be identified thro specific physiological ‘markers’ kinked to certain crime types. ‘atavistic’ characteristics mainly featured head + face, made criminals diff.cranial features, atavistic form included narrow, sloping brow, strong prominent jaw + high cheekbones, dark skin and existence of extra toes, fingers + nipples. categorise certain particular types of criminals - physical characteristics. Murderers described as having bloodshot eyes, curly hair + long ears, sexual deviants - glinting eyes and swollen, fleshy lips, lips of fraudsters were thin + reedy.
Lombroso Research
meticulously examined facial features of 100 Italian convicts, living + dead, + proposed atavistic form associated w n.o of physical anomalies which were key indicators of criminality. examined skulls of 383 dead criminals + 3839 living ones, + concluded that %40 of criminal acts could be accounted for by atavistic characteristics.
Atavistic Evalution - (contribution to criminology)
P - Lombroso named as ‘father of modern criminology .
E - shifted emphasis from moralistic discourse where offenders were judged as being wicked + weak minded towards more scientific realm of evolution + genetics.
E - In Trying to describe physical characteristics of particular crimes + criminals, this was start of criminal profiling, made major contribution to the science of criminology.
I - other criminologists were able to build upon his ideas of genetics + physical features, w use of modern day technology to accurately profile criminals
Atavistic Evalution - (scientific racism)
P - DeLisi drawn attention to distinct racism within Lombroso’s work.
E - Features Lombroso described r curly hair + dark skin - most likely found amongst people of African descent.
E - Whether Lombroso intended to, there is controversial aspect of his legacy, continues to overshadow criminology + criminologists need to be careful when profiling + identifying criminals.
Atavistic Evalution - (cause and effect)
P - Even if there r criminals w atavistic features like Lombroso suggested,doesn’t mean this the cause of their offending.
E - Facial + cranial differences may be influenced by other factors like poverty + poor diet rather an indication of delayed evolutionary development.
E - In later work, Lombroso acknowledged criminals could be made as well as born due to range of environmental factors.
I - there r people possess atavistic features that aren’t criminals + also be people possess atavistic features that are criminals.means facial features aren’t necessarily cause to someone’s behav
Genetic Explanations
Genes consist of DNA strands - produces instructions for general physical features of organism + specific physical features. may impact on psychological features. Genes transmitted from parents to offspring.
Genetics - Twin studies
suggests would-be offenders inherit gene/genes that predispose them to commit crime. Lange : looked at
13 MZ + 17 DZ twins.
1 twin served time in prison.
10 MZ + 2 DZ other twin been in prison
Genetics - adoption studies
50% adopted children whose mum who had been in prison had also been arrested.
Adopted children who’s mother hadn’t been in prison, 5% were arrested
Genetics - diathesis stress model
tendency towards criminal behaviour may come about thro effects of environ - combination of genetic predisposition + biological or psychological trigger e.g. criminal role models.
Neural Explantion
explanation of behav & disorders in terms of (dys)functions of brain + nervous system. includes activity of brain structures like hypothalamus, + neurotransmitters like serotonin + dopamine.
Neural - cortex
neural differences in brains of criminals and non-criminals.
Most evid w indiv diagnosed w APD (antisocial personality disorder/psychopathy) - reduced emotional responses, lack of empathy + these r characteristics of many convicted criminals.
reduced prefrontal cortex activity (regranted emotional behav) - raine found 11% reduction in vol of grey matter compared to controls
Neural - mirror neurons
criminals w APD can experience empathy but do more sporadically than normal people. Keysers (2011) found only when criminals were asked to empathise w someone did their empathy reaction activate.
Controlled by mirror neurons. Watching someone on film experience pain.
APD people aren’t totally w/out empathy but may have neural ‘switch’ unlike ‘normal’ brain
Genetic Evalution - adoption
P - Many children experience late adoption.
E - means much of child’s infancy + childhood may spent w bio parents.
E - results found in adoption studies may not account for environ impact bio parents have
I - reducing validity, can’t determine the cause is entirely due to non bio parents
Genetic Evaluation - Candidate genes
P - candidate genes a deterministic explanation
E - focuses on genes like MAOA to explain criminal behav .
E But, criminality is complex, + may be inappropriate + overly simplistic to only focus on biology in offending behav.
I - should consider environ influences like childhood trauma
Genetic Evaluation- free will
P - MAOA + CDH13 gene have been implicated in violent crime.
E / suggests criminal behav is beyond indiv control.
E - But this problematic as our legal system is based on criminals having personal + moral responsibility, raises ethical q bout how violent criminals should be treated.
I - if remove connotation of free will, hard to distinguish what is punishable as crime
Neural Evalution - grey matter
P - support of bio explanation
E - Rainefound 11% reduction vol of grey matter in prefrontal cortex of people w antisocial personality disorder compared to controls.
E - increases val of explanation as suggests neural differences in brains of criminals + non-criminals.
I - raises q whether criminals r predetermined by human bio
Neural Evaluation - empathy support
P - evid to support criminals have empathy
E - Keysers found only when criminals were asked to empathise w person depicted on film experiencing pain did empathy reaction, controlled by mirror neurons in brain, activate.
E - suggests APD indiv do have some empathy but may have neural
‘switch’ that can be turned on/off, unlike “normal” brains where empathy is permanently turned on.
I - q how genuine behav when showing empathy or using for own benefit
Neural Evlaution - incomplete
P - bio explanation incomplete
E - found in Raine, could be cause
encerator of offending behav or result of some environ factor, in turn makes more likely to become a criminal.
E - matters as highlights complexity of relationship between bio + behav + suggests further investigation is required.
I - reduces validity of explanation as doesn’t consider all influences like environ
Eysenck’s theory of personality
behaviour represented w 2 dimensions:
Introversion/Extroversion (E) - underactive nervous systems so seek stimulation, don’t condition easily, don’t learn from mistakes.
Neuroticism/Stability (N) - difficult to predict, instability, jumpy
two dimensions combine to form variety of personality characteristics.
later added 3rd dimension: Psychoticism (P).
personality traits have bio orgin + come from type of nervous system we inherit. all personality have innate bio basis
