forensics Flashcards
what are the two types of offender profiling
top down, bottom up
what is the top down approach
american
typology approach
Based 36 interviews with serial rapists and killers
offender is matched to a pre-existing template made by the FBI
2 categories-
organised offenders- plan crime, high degree of control, few clues left, above average IQ, professional occupation
disorganised offenders- spontaneous crime, little control, low IQ, unskilled, history of sexual dysfunction
4 stages:
1. data assimilation- review crime scene
2. classification- organised vs disorganised
3.crime reconstruction- hypothesis on the terms of what happened
4. profile generation- hypothesis related to the offender
what are the four stages of constructing an FBI profile
- data assimilation
- classification
- crime reconstruction
- profile generation
evaluation top down approach
- only useful for crimes that reveal a lot about the offender- such as rape, serial killings. More common crimes don’t reveal much information about the offender. Only useful for certain crimes
- Canter suggested there is not enough support for the disorganised offender. analysed 100 murders in the USA. Found evidence for the organised type but not the disorganised type. Poor validity when identifying subjects.
- approached was formed from interviews with 36 of the most dangerous criminals who are highly manipulative. The approach for more typical offenders might be different. Sample is small and hard to generalise. Lowers validity and be cautious when using on all criminals.
+ approach is useful. Copson questioned 184 police officers and found that 82% said the technique was was operationally useful and 90% said they would use it again. However, further evidence suggests that although it was useful it did not always lead to identification. Only in 3% of cases.
-some have criticized the approach saying that it is only guess work and that profilers are not necessary. Kocsis et al found that chemistry students produced a more accurate profile than actual profilers.
what is the bottom up approach
british
investigative approach
data collected from crime scenes to develop a hypothesis
patterns are identified and info is compared to a statistical database
interpersonal coherence-how the offender behaves at the crime scene and time and place are important to indicate where the offender lives
geographical profiling- used in conjunction with psychological theory to create a hypothesis about what the offender is thinking. Crime location and finding the ‘centre of gravity’ to see the area of crime. Base is often in the middle.
Evaluate the bottom up approach
+ seen as more scientific than the FBI approach as it uses objective statistics. Although the info tells us about offenders that have been caught not about offenders who haven’t been caught. Reduces validity and generalisability
+ evidence to support comes from Canter who conducted an analysis of 66 sexual assaults’ using a programme called small space analysis that identifies correlations and patterns. Common characteristics were found. eg lack of reaction, use of impersonal language. supports investigative psychology and how statistics can be applied.
+ british approach has a wider application than the american approach. techniques such as the small space analysis can be used on a range of crimes, not just extreme crimes. More useful for catching criminals.
What is the biological explanation of offending behaviour- historical approach?
atavistic form:
proposes criminals are a subspecies of genetic throwbacks that cannot conform to the rules of normal society. Such individuals are distinguishable due to their facial features. Lombroso suggested offenders possessed similar characteristics to lower primates and this could explain their criminality.
‘born criminal’ theory- 3000 anthropometric measurements.
-unusual size of heas
-facial asymmetry
-extended jaw
-too big/small ears
-full lips
-abnormal teeth
-wrinkled skin
-nose curled up
based on post mortems of dead criminals and studying living criminals
383 convicted italian criminals- 21% had 1 trait 43% had at least 5
recognised inherited atavistic form interacted with their environment
distinguished three types of criminals
born- atavistic type
insane- suffering mental illness
criminaloids- people who’s predisposed mental characteristics predispose them to crime under certain circumstances
evaluate the atavistic form
- lack of control. He didn’t study non-prisoners. could have been the case that non-prisoners had the same characteristics. Goring studies both and found no significant difference.
+large sample size so can be generalized to the target population
-gender bias, believed that women were less evolved than men. Believed women were jealous, insensitive to pain, passive, possess maternal instincts and low in intelligence. these factors made them less likely to commit a crime. Women who committed crimes had masculine traits which were positive in a man but created a monster in a woman. He didn’t study women so it can’t be generlised Low validity and low credibility.
-bias in terms of scientific racism. he identified characteristics that were typical in a criminal but they were also african american traits. Reflected the view of society at the time and may not be accurate - issue with cause and effect. the relationship between the two variables doesn’t mean one is causing the other. facial differences may be caused by poor diet or poverty and may not be a result of evolutionary development. biological reductionism
+ good contribution to criminology, shifted the focus from a moralistic basis to a scientific basis, credited for started the area of criminal profiling.
what is the genetic explanation offender behavior
offenders inherit a combination of genes that predispose them to crime. Investigated by using twin studies. MZ and DZ were compared or MZ that had been separated.
Candidate gene in offending. two genes have been identified. MAOA gene (responsible for controlling dopamine and serotonin) and CDH13. MAOA has been linked to aggressive behaviour and CDH13 has been linked to substance abuse and attention deficit disorder. Tiihonen et al analysed 900 offenders and found the two genes were responsible for the offending behaviour.
diathesis stress model states that genes are switched on and off by epigenomes which have been affected by the environment. eg abuse or maltreatment in childhood or criminal role models in family.
evaluate the genetic explanation
+ research to support came from adoption studies. Mednick et al studies 14000 adoptees and found that 15% of sons adopted by a criminal family went on to become criminals where as 20% of adoptees with criminal biological parents became criminals. Inherited genes are marginally a more significant factor. Hard when they are adopted late and spent time with their biological parents.
-problem with the use of twin studies. early research of twins was poorly controlled. Also categorised MZ and DZ based on their physical characteristics . Sample sizes were small so don’t represent the who target population. also doesn’t represent the twins that were brought up in the same environment. Hard to know if its nature or nurture.
- biological reductionism. says that a person born with specific genes will develop certain characteristics. Tiihonen et al found that those with the defective gene were 13 times more likely to have a history of repeated violence. This means not everyone who has the gene will most likely become an offender. there may be other reasons and we need to take a more holistic approach
what is the neural explanation for offending behaviour
brain abnormalities have been linked to crimes.the prefrontal cortex of the brain is likely to be abnormal according to some research. this part of the brain regulates emotional and moral behaviour. Raine looked at 71 brain image studies showing that murderers, psychopaths and violent people have reduced functioning in the prefrontal cortex. low activity in this area is also linked to impulsiveness and loss of control.
parts of the limbic system may also be linked. the thalamus and amygdala have been linked to emotion and motivation. Raine et al in another study found that murders not guilty due to insanity gave reduced activity on the left side of the amygdala and increased activity on the right compared to a matched control group of non-murders.
neurotransmitters such as serotonin may also be involved in criminal behaviour . low levels of serotonin are thought to influence criminal behaviour. serotonin also inhibits the function of the prefrontal cortex. furthermore, high and low levels of noradrenaline have been associated with aggression, violence and criminality, noradrenaline helps people perceive threats so a low amount would reduce this ability
evaluate the neural explanation
- although neurotransmitters such as neuro adrenaline are linked to crime the relationship is casual. meaning the cause and effect can’t be established. this is also the case for brain abnormalities.
- could be problems with the methodology used to study offending. most of the research is done on animals. in this case aggression is studies and not so much criminal behaviour.issue with generalising findings to humans as well as crimes.animals have less complex brains than humans.also not all crimes stem from aggressive behaviour so this might not be relevant to non aggressive crimes.
+ has application. enables us to find ways of treating criminal behaviour or preventing it. if low levels of serotonin cause aggressiveness then people in prison could be given a diet to increase the serotonin they get or medication
what is Eysenck’s theory of personality
personality could be represented on two dimensions: introvert/ extrovert: extroverts are outgoing have high positive emotions and get bored easily. introverts are more reserved and quiet. extroverts have an underactive nervous system so they constantly seek excitement and like to engage in risk taking behaviour.
neuroticism/ stability: neuroticism is the tendency to experience negative emotional states rather than positive emotional states. neurotic people tend to be nervous, angry and hard to predict.
Eysenck believed out traits were biological and inherited. the criminal personality type tends to be neurotic extrovert. Eysenck also claimed that a criminal will also score highly on the psychoticism score. psychoticism has been linked to high levels of testosterone.
Eysenck believed that criminals were developmentally immature and their high E/N scores make it hard for them to socialise and hard to train them to be more socially orientated. He developed the Eysenck personality inventory (EPI) to measure the personality types.
evaluate Eysenck’s theory of personality
- personality may not be consistent. theory assumes someone who is anxious is like that all the tim. however people behave differently in different situations.Mischel and peake supported the idea. they asked family, friends and strangers to rate 63 students in a variety of situations and found no correlation between traits. idea is flawed because people do not have ‘one’ personality
+ Eysenck and Eysenck supports. compared 2000 male prisoners scores on the EPI with over 2000 male controls. divided into age groups 16-69 and measured on P/N/E. They found that prisoners always scored higher than the controls. Large sample size so high in population validity and generalisability and means we can use it as a valid support study
-method may be flawed. EPI questionnaire required yes/ no answers and may not fit accurately with the individual’s actual answer. demand characteristics may come into play if the pp lies on the questionnaire. This reduces the validity. - cultural differences that the theory doesn’t take into account. Bartol and holanchock studied hispanic and african american convicts in a maximum security prison and found that they were less extroverted than the non-criminal control group. can’t generalize.
- suggests personality may have a genetic basis and therefore supports the biological argument. research has shown a genetic link in neuroticism and extrovertedness. twin studies have found a genetic lin, however there is not a 100% concordance rate suggesting environmental influences may be a factor. Biological reductionism.
what is the cognitive explanations
- level of moral reasoning
- cognitive distortions
- differential association theory
- psychodynamic theory
