forensic psychology Flashcards
offender profiling
a behavioural and analytical tool that is intended to help investigators accurately predict and profile the characteristics of unknown offender
what are the two types of offending profiles
top down and bottom up approach
the top down approach
profilers start with a pre established typology and work down to lower levels in order to assign offenders to one of two categories based on witness account and evidence of crime scene
what are the two types of offenders
organised and disorganised
who are organised offenders
offender who shows evidence of planning,targets a specific victim and tends to be socially and sexually competent with higher than average intelligence
who are disorganised offenders
offender who shows little evidence of planning,leave clues and tends to be socially and sexually incompetent with lower than average intelligence
how to construct an FBI profile
1.data assimilation- review of evidence (crime scene photos,witness reports etc)
2.crime scene classification- either organised or disorganised
3.crime reconstruction- hypotheses in terms of sequence of events,behaviour of victim etc
4.profile generation- hypotheses related to the likely offender like physical characteristics
evaluation 1- research support( top down approach)
-strength
-Canter et al. conducted an analysis of 100 US murders each committed by a different serial killer.
-analysis was used in order to assess the co-occurrence of 39 aspects of serial killings.
-This analysis revealed that there does seem to be features of many serial killings which matched the FBI’s typology for organised offenders.
-This suggests that a key component of the FBI typology approach has some validity.
evaluation 2- counterpoint of research support( top down approach)
-There are a variety of combinations that occur at any given murder scene.
-e.g. Godwin argues that it is difficult to classify killers as one or the other type.
-A killer may have multiple contrasting characteristics, such as high intelligence but commits a spontaneous murder leaving the victim’s body at the crime scene.
-This suggests that the organised-disorganised typology is probably more of a continuum.
evaluation 3- wider application ( top down approach)
-strength
-it can be adapted to other kinds of crime, such as burglary.
-Meketa reports that top-down profiling has recently been applied to burglary, leading to an 85% rise in solved cases in three US states.
-The detection method also adds two new categories: interpersonal (offender usually knows their victim and steals something of significance) and opportunistic (generally inexperienced young offender).
-This suggests that top-down profiling has wider application than was originally assumed.
evaluation 4-flawed evidence ( top down approach)
-limitation
-flaw on the evidence it is based on.
-FBI profiling was developed using interviews with 36 murderers in the US
-Canter et al. have argued that the sample was poor
-the FBI agents did not select a random or even a large sample nor did the sample include different kinds of offender.
-There was no standard set of questions so each interview was different and therefore not really comparable.
-This suggests that top-down profiling does not have a sound, scientific basis.
what is the bottom up approach
profilers work up from evidence collected from the crime scene to develop hypotheses about likely characteristics, motivations and social background of offender
Investigative psychology- bottom up approach
-The aim, in relation to offender profiling, is to establish patterns of behaviour that are likely to occur across crime scenes.
-This is in order to develop a statistical database which then acts as a baseline for comparison.
-Specific details of an offence, or related offences, can then be matched against this database to reveal important details about the offender, their personal history, family background, etc.
-This may also determine whether a series of offences are linked in that they are likely to have been committed by the same person.
-Central to the approach is the concept of interpersonal coherence - that the way an offender behaves at the scene, including how they ‘interact with the victim, may reflect their behaviour in more everyday situations.
- e.g. some rapists want to maintain maximum control and humiliate their victims, others are more apologetic (Dwyer ).
-This might tell police something about how the offender relates to women more generally.
Geographical profiling- bottom up approach
-Geographical profiling uses information about the location of linked crime scenes to make inferences about the likely home or operational base of an offender - known as crime mapping and based on the principle of spatial consistency (that people commit crimes within a limited geographical space).
- Canter’s circle theory (Canter and Larkin ) state the pattern of offending forms a circle around the offender’s home base.
- distribution of offences leads us to describe an offender in one of two ways:
The marauder - who operates in close proximity to their home base.
The commuter - who is likely to have travelled a distance away from their usual residence.
evaluation 1- evidence for investigative psychology ( bottom up approach)
- strength of investigative psychology
- evidence supports its use.
- Canter and Heritage conducted an analysis of 66 sexual assault cases.
-The data was examined using smallest space analysis
-Several behaviours were identified as common in different samples of behaviour, such as the use of impersonal language and lack of reaction to the victim.
-Each individual displayed a characteristic pattern of such behaviours and this can help establish whether two or more offences were committed by the same person.
-This supports one of the basic principles of investigative psychology (and the bottom-up approach) that people are consistent in their behaviour.
evaluation 2- counterpoint of evidence for investigative psychology ( bottom up approach)
-However, case linkage depends on the database and this will only consist of historical crimes that have been solved.
- The fact that they were solved may be because it was relatively straightforward to link these crimes together in the first place.
-Which makes this a circular argument.
- This suggests that investigative psychology may tell us little about crimes that have few links between them and therefore remain unsolved.
evaluation 3-evidence for geographical profiling ( bottom up approach)
-strength
-evidence to support geographical profiling
-Lundrigan and Canter collated information from 120 murder cases involving serial killers in the US.
-Smallest space analysis revealed spatial consistency in the behaviour of the killers.
-The location of each body disposal site created a centre of gravity when
-offenders start from their home base and may go in a different direction each time they dispose of a body, but in the end all these different sites create a circular effect around the home base
-The effect was more noticeable for offenders who travelled short distances (marauders).
-This supports the view that geographical information can be used to identify an offender.
evaluation 4- geographical information insufficient ( bottom up approach)
- limitation
-geographical profiling may not be sufficient on its own.
-the success of geographical profiling may be reliant on the quality of data that the police can provide. - recording of crime is not always accurate, can vary between police forces and an estimated 75% of crimes are not even reported to police in the first place
- Even if this information is correct, critics claim that other factors are just as important in creating a profile, such as the timing of the offence and the age and experience of the offender (Ainsworth ).
-This suggests that geographical information alone may not always lead to the successful capture of an offender.
what are the three biological explanations for offending
atavistic form,genetic and neural
Historical approach-atavistic form
- Lombroso wrote a book in which he suggested that criminals were genetic throwbacks’ - a primitive subspecies who were biologically different from non-criminals.
biological approach- atavistic form
- Lombroso saw offending behaviour as a natural tendency, rooted in the genes of those who engage in it.
- At the time he was writing, Lombroso was proposing a new perspective - that offending behaviour was innate and therefore an offender was not to blame for his actions.
-In this way, his ideas were revolutionary
atavistic form and characteristics
-offenders had particular physiological ‘markers’ that were linked to particular types of offence.
-These are biologically determined ‘atavistic’ characteristics, mainly features of the face and head that make offenders physically different from the rest
-In terms of cranial (skull) characteristics, the atavistic form included a narrow, sloping brow, a strong prominent jaw, high cheekbones and facial asymmetry.
-Other physical markers included dark skin and the existence of extra toes, nipples or fingers.
-Lombroso suggested there were other aspects of the born offender including insensitivity to pain, use of slang, tattoos and unemployment
offender types- atavistic form
- Murderers were described as having bloodshot eyes, curly hair and long ears
- sexual deviants had glinting eyes, swollen, fleshy lips and projecting ear
-lips of fraudsters were thin and reedy
lombroso’s research- atavistic form
-Lombroso examined the skulls of 383 dead convicts and 3839 living ones
-40% of criminal acts were committed by people with atavistic characteristics.
evaluation 1- Lombroso’s legacy (atavistic form)
- strength
-his work changed the face of the study of crime.
-he has been hailed as the father of modern criminology - He shifted the emphasis in crime research away from a moralistic discourse towards a more scientific position ( genetics )
- in trying to describe how particular types of people are likely to commit particular types of crime, Lombroso’s theory heralded the beginning of offender profiling of criminology.
-This suggests that Lombroso made a major contribution to the science of criminology
evaluation 2-counterpoint of Lombroso’s legacy (atavistic form)
- several critics, including DeLisi, have questioned whether Lombroso’s legacy is entirely positive.
-it has racist undertones - Many of the features that Lombroso identified as atavistic (curly hair, dark skin) are most likely to be found among people of African descent.
-he is suggesting that Africans were more likely to be offenders, a view that fitted 19th-century eugenic attitudes.
-This suggests that some aspects of his theory were influenced by racial prejudices of the time.
evaluation 3- contradictory evidence (atavistic form)
-limitation
-evidence contradicts the link between atavism and crime.
- Goring conducted a comparison between 3000 offenders and 3000 non-offenders and concluded that there was no evidence that offenders are a distinct group with unusual facial and cranial characteristics
-but suggested that many people who commit crime have lower-than-average intelligence.
-This challenges the idea that offenders can be physically distinguished from the rest of the population and are therefore unlikely to be a subspecies.
evaluation 4- poor control (atavistic form)
-limitation
-Lombroso failed to control important variables within his research.
-Unlike Goring, he did not compare his offender sample with a non-offender control group.
-This could have controlled for an assortment of confounding variables that might have equally explained higher crime rates in certain groups of people. -e.g.research has demonstrated links between crime and social conditions such as poverty and poor educational outcomes (Hay and Forrest)
-This suggests that Lombroso’s research does not meet modern scientific standards
what do genetic explanations for crime suggest
suggest that would-be offenders inherit a gene that predispose them to commit crime
twin and adoptions studies- genetic explanations for crime
-Christiansen studied over 3500 twin pairs in Denmark, and found concordance rates for offender behaviour of 35% for identical twin (MZ) males and 13% for non-identical twin (DZ) males
-This data indicates that it is not just the behaviour that might be inherited but the underlying predisposing traits.
-Crowe found that adopted children whose biological mother had a criminal record had a 50% risk of having a criminal record by the age of 18, whereas adopted children whose biological mother didn’t have a criminal record only had a 5% risk.
candidate genes- genetic explanations for crime
-A genetic analysis of almost 800 Finnish offenders by Tihonen et al suggested that two genes (MAOA and CDH13) may be associated with violent crime.
-The MAOA gene regulates serotonin in the brain and has been linked to aggressive behaviour
-CDH13 gene has been linked to substance abuse and attention deficit hyperactivity disorder.
-The analysis found that about 5-10% of all severe violent crime in Finland is attributable to the MAOA and CDH13 genotypes.
diathesis stress model- genetic explanations for crime
-A tendency towards offending behaviour may come about through the combination of genetic predisposition and biological or psychological trigger
-e.g. being raised in a dysfunctional environment or having criminal role models.
evaluation 1- issues with twin studies ( genetic explanations for crime)
-limitation
-It is assumed by researchers studying twins that environmental factors are held constant because twins are brought up together and therefore must experience similar environments.
-However, this shared environment assumption may apply much more to MZ twins than DZ twins because MZ twins look identical and people tend to treat them more similarly which, in turn, affects their behaviour.
-Therefore higher concordance rates for MZs in twin studies may simply be because they are treated much more similarly than DZ twins.
evaluation 2- support for diathesis stress ( genetic explanations for crime)
-strength
-support for the diathesis-stress model of offending.
-A study of 13,000 Danish adoptees was conducted by Mednick et al and when neither the biological nor adoptive parents had convictions, the percentage of adoptees that did was 13.5%
- This figure rose to 20% when either of the biological parents had convictions
-24.5% when both adoptive and biological parents had convictions.
-This shows that genetic inheritance plays an important role in offending but environmental influence is clearly also important, providing support for the diathesis-stress model of crime.
what do neural explanations of crime suggest
that there may be differences in brain structures and neurotransmitters of offenders and non offenders
prefrontal cortex- neural explanations for crime
-Raine demonstrated that individuals with antisocial personalities have reduced activity in the prefrontal cortex, the part of the brain that regulates emotional behaviour.
-also Raine and his colleagues found an 11% reduction in the volume of grey matter in the prefrontal cortex of people with APD compared to controls.
mirror neurons - neural explanations for crime
-Keysers found that only when offenders were asked to empathise did their empathy reaction (controlled by mirror neurons ) activate.
-This suggests that APD individuals are not totally without empathy, but may have a neural ‘switch’ that can be turned on and off, unlike the ‘normal’ brain which has the empathy switch permanently on
evaluation 1- brain evidence ( neural explanations for crime)
-strength
-there’s support for the link between crime and the frontal lobe.
-Kandel and Freed reviewed evidence of people with frontal lobe damage who tended to show impulsive behaviour, emotional instability and an inability to learn from their mistakes.
-The frontal lobe is associated with planning behaviour.
-This supports the idea that brain damage may be a causal factor in offending behaviour.
evaluation 2- intervening variables ( neural explanations for crime )
-limitation
-link between neural differences and APD may be complex.
-Farrington et al studied a group of men who scored high on psychopathy (APD).
-These individuals had experienced various risk factors during childhood, such as being raised by a convicted parent and being physically neglected.
-It could be that these early childhood experiences caused APD and also some of the neural differences associated with it - such as reduced activity in the frontal lobe due to trauma (Rauch et al. 2006).
-This suggests that the relationship between neural differences, APD and offending is complex
what are the psychological explanations for crime
-Eysenck’s theory ( criminal personality)
-cognitive: levels of moral reasoning and cognitive distortions
-Differential association theory ( DAT)
-psychodynamic
what is the criminal personality
-a feature of Eysenck’s theory of crime
-an individual who scores high on extraversion, neuroticism and psychoticism is cold and unfeeling
-and is likely to engage in offending behaviour
why are extraverts more likely to offend
-have an underactive nervous system which means they constantly seek excitement, stimulation and are likely to engage in risk-taking behaviours.
-They also tend not to condition easily and therefore do not learn from their mistakes.
why are neurotic individuals more likely to offend
-have a high level of reactivity in the sympathetic nervous system - they respond quickly to situations of threat (fight or flight).
-This means they tend to be nervous, jumpy and overanxious, and their general instability means their behaviour is often difficult to predict.
why are psychotic individuals more likely to offend
individuals are suggested to have higher levels of testosterone and are unemotional and prone to aggression.