Forensic Psychology - Coggle Diagram
- Crow (1972) found that adopted children who had a biological parent with a criminal record had a 50% risk of having a criminal record by 18, whereas adopted children whose mother didn’t have a criminal record only had a 5% risk.
- Tiihonen et al (2014) revealed two abnormalities that may be associated with violent crime – the MAOA gene (controls dopamine and serotonin) and CDH13 (linked to substance abuse and attention deficit disorder). Tiihonen’s sample was 900 Finnish offenders. Individuals with this combination were 13 times more likely to have a history of violent behaviour. This research is in its infancy and has yet to be replicated.
- MAOA gene: controls dopamine and serotonin in the brain and has been linked to aggressive behaviour
- Lange (1930); 13 MZ twins and 17 DZ twins where one of the twins in each pair has spent time in prison. 10 of the MZ twins and but only 2 of the DZ twins had a co-twin that had also spent time in prison.
- Christiansen (1977) examined over 3,500 twin pairs in Denmark and identified concordance rates of criminal behaviour as follows:
- Male: Mz- 35%, Dx - 13%
- Female: Mz - 21%, Dz - 8%
- The findings are interesting as they indicate a degree of inheritance; however, there are some key points to consider.
- Firstly, the concordance rates are low, even for monozygotic twins, which indicates that the environment still plays a large part in criminal behaviour.
- Secondly, the difference between male and female twin pairs raises an interesting question about the role of gender in criminal behaviour.
:red_cross: Problems with the twin studies:
- Early twin studies of criminality were poorly controlled, and judgments related to zygosity were based on appearance rather than DNA testing.
- Also, they only use small sample sizes, they may not represent the rest of the population.
- There is a major confounding variable that they are in the same environment, as concordance rates may be due to shared learning experiences rather than genetics.
:red_cross: Support for the diathesis-stress model/ ignores environmental factors:
- A major study of over 13,000 Danish adoptees was conducted by Mednick et al.
- Conviction rates 13.5% (biological/adoptive parents had no convictions), 20% (1 biological parent), and 24.5% (both adoptive and biological parents).
- This data suggest that both genetic inheritance and environment influence criminality.
- Individuals who experience antisocial personality disorder show reduced activity in the PFC, the part of the brain that regulates emotional behaviour. Raine (2000) found an 11% reduction in the volume of grey matter in the PFC of people with APD compared to control groups.
:check: Support for the link between crime and the frontal lobe:
- Kandel and Freed (1989) researched people with frontal lobe damage, including the prefrontal cortex.
- They found evidence of impulsive behaviour, emotional instability and inability to learn from mistakes.
- This supports the idea that structural abnormalities in the brain are a causal factor in offending behaviour.
:red_cross: The link between neural differences and APD is complex:
- Farrington et al (1981) studied adult males with high APD scores. They were raised by a convicted parent and physically neglected.
- These early experiences may have caused APD and associated neutral differences, e.g., reduced activity in the frontal lobe due to trauma.
- This suggests that the relationship between neural differences, APD and offending is complex and there may be intervening variables.
Mirror neurons: Keysers (2011):
- Only when criminals were asked to empathise with others did their empathy reactions activate. This is controlled by mirror neurons. This suggests that criminals do experience empathy, although it is not an automatic response. These neurons fire in response to the actions of others.
The top-down approach
The top-down approach:
- Described as a qualitative approach
- Based on police experience and case studies.
- Suitable for more extreme/unusual crimes.
- The phrase top-down refers to an approach which starts with the big picture and then fills in the details, this contrasts with a bottom-up approach which starts with details and creates the big picture.
- In 1980 Hazelwood and Douglas published their account of the ‘lust murderer’, they advanced a theory that lust murderers are many categorised into two types:
- Leads an ordered life and kills after some sort of critical life event.
- Their actions are premeditated and planned, they are likely to bring weapons and restraints to the scene.
- They are likely to be of average to high intelligence and employed.
- Ted Bundy is an example of an organised killer.
- More likely to have committed the crime in a moment of passion.
- There will be no evidence of premeditation and they are more likely to leave evidence such as blood, semen, murder weapon etc. behind.
- This type of offender is thought to be less socially competent and more likely to be unemployed.
Constructing an FBI profile:
- There are 4 main stages:
- Data assimilation - the profiler reviews the evidence.
- Crime scene classification - as either organised or disorganised.
- Crime reconstruction - hypotheses in terms of a sequence of events, the behaviour of the victim etc…
- Profile generation - hypothesis related to the likely offender, e.g., of demographic background, physical characteristics, behaviour etc…
:red_cross: Evidence to show it doesn’t support the disorganised offender:
- Canter et al (2004) using a technique called smallest space analysis, analysed data from 100 murders in the USA.
- The details of each case were examined with reference to 39 characteristics thought to be typical of organised and disorganised killers.
- Although the findings did indeed suggest evidence of a distinct organised type, this wasn’t the case for disorganised which seems to undermine the classification system.
:red_cross: Only applied to extreme offenders:
- Top-down profiling is best suited to crime scenes that reveal important details about the suspect, such as rape, arson, and cult killings, as well as crimes that involve macabre practices such as sadistic torture.
- More common offences such as burglary don’t lend themselves to profiling because the resulting crime scenes reveal very little about the offender.
- This means that it’s a limited approach to identifying a criminal.
:red_cross: Based on outdated models of personality:
- The typology classification system assumes that offenders have patterns of behaviour and motivations that remain consistent across situations and contexts.
- Several critics have suggested that this approach is naïve and is informed by old-fashioned models of personality that see behaviour as being driven by stable dispositional traits rather than external factors that may be constantly changing.
- This means the top-down approach is likely to have poor validity when it comes to identifying possible suspects and/or trying to predict their next move,
The bottom-down approach
- Canter (1990) is the UK’s foremost profiling expert, his bottom-up approach looks for consistencies in offenders’ behaviour during the crime. No initial assumptions are made about the offender and the approach relies heavily on computer databases. It can be the little details that are often overlooked that can be crucial to the success of a case.
The circle theory:
- Circle Theory proposes two models of offender behaviour. People operate within a limited spatial mindset that creates imagined boundaries in which crimes are likely to be committed.
- The Marauder:
- The offender operates near their home base.
- The Commuters:
- The offender is likely to have travelled a distance away from their usual residence.
:check: One strength is that evidence supports investigative psychology:
- Canter and Heritage conducted an analysis of 66 sexual assault cases smallest space analysis. Several behaviours were identified in most cases.
- Everyone displayed a pattern of such behaviours, which helps establish whether 2 or more offences were committed by the same person.
- This supports one of the basic principles of investigative psychology that people are consistent with their behaviour.
:check: Another strength is that evidence supports geographical profiling:
- Lundrigan and Canter collated information from 120 murder cases in the US. The smallest space analysis revealed spatial consistency.
- Offenders leave their home base in different directions when dumping a body but created a circular effect, especially in the case of marauders.
- This supports the view that geographical information can be used to identify an offender.
:red_cross: One limitation is that geographical profiling may not be sufficient on its own:
- Recording of crime is not always accurate, can vary between police forces and an estimated 75% of crimes aren’t reported to the police.
- Even if crime data is correct, other factors matter e.g., the timing of the offence and age etc…
- This suggests that geographical information alone may not always lead to the successful capture of an offender.
- Interpersonal coherence:
- This is the way in which an offender behaves at the scene. How they interact with the victim may indicate how they act in everyday life.
- Significance of time and place:
- This may indicate where the offender is living if the crimes take place within the same forensic ‘’centre of gravity’’.
- Forensic awareness:
- This focuses on those who have been the focus of police attention before. Their behaviour may denote how mindful they are of covering their tracks.
- Rossmo (1997) stated that an offender’s operational base of possible future offences is revealed by the geographical location of their previous crimes. This is known as ‘crime mapping’.
- Serial offenders will restrict their ‘’work’’ to areas they are familiar with and so understanding the spatial pattern of their behaviour provides investigators with a ‘’centre of gravity’’ which is likely to include the offenders’ base.
Canter and Heritage:
- Aim: To identify a behaviour pattern from similarities between offences.
- Methodology: Canter analysed the co-occurrence of 48 crime scenes and offender characteristics are taken from 82 murder cases where the victim was a stranger.
- Results: They identified 3 themes:
1. Instrumental Opportunistic – “instrumental” refers to using murder to obtain something or accomplish a goal. ‘’Opportunistic” means that the offender took the easiest opportunities
- Instrumental cognitive – a concern about being detected and therefore they are more planned
- Expressive Impulsive – uncontrolled, in the heat of strong emotions, may feel provoked by the victim.