Forensics Flashcards
Define: Crime
An act committed in violation of the law where the consequence of conviction by a court is punishment.
What are the problems associated with the crime definition?
- Historical issues - laws are often subject to change (eg. Homosexuality)
- Cultural issues - cultural variations (eg. Bigamy)
- Not all acts that break the law are punishable
What are the 3 ways of measuring crime?
- Official statistics
- Victim surveys
- Offender surveys
Describe official statistics
- Official statistics are government records of the total number of crimes reported to police and recorded in official figures.
- These allow the government to develop crime prevention strategies and policing initiatives.
Describe victim surveys
- Victim surveys record people’s experience of crime over a specific period of time, and whether or not they have been reported to the police.
- 50,000 randomly selected households in England and Wales.
Describe offender surveys
- Offender surveys involve individuals volunteering details of the number and types of crimes they have committed, over a specified period.
- Target groups of likely offenders based on ‘risk factors’ such as previous convictions.
Evaluate defining and measuring crime
- Official statistics is unreliable, underestimating the extent of the crime - unreported/unrecorded crimes cannot be included - only 25% are. Some areas report crime more, eg. Nottinghamshire record thefts of under £10.
- Victim surveys have a greater degree of accuracy, more likely to include details of crime - 2006/7, official status said 2% decrease in crime whereas victim surveys said 3% increase. However, victim survey relies on recall so telescoping can occur.
- Offender survey responses are unreliable - may want to conceal/exaggerate the number of crimes committed. Also certain types of crime such as burglary are over represented whilst ‘middle-class’ offences are unlikely to be included.
- When measuring crime, political parties will interpret differently - party in power will emphasise statistics which show that crime is falling, opposing parties would focus on measures that make the party look bad.
Define: Offender profiling
A behavioural and analytical tool that is intended to help investigators accurately predict and profile characteristics of unknown criminals.
Describe the top-down approach
- Originated in the US, also known as ‘the American approach’ or the ‘typology approach’.
- What is known about the crime and the offender is matched to a pre-existing template that the FBI developed.
- Offenders are classified in to one of two categories (organised or disorganised) on the basis of the evidence from the crime scene and witness accounts.
- Both classifications are distinct due to the basis that serious offenders have certain ways of thinking, known as their ‘modus operandi’. These generally correlate with a particular set of social and psychological characteristics that relate to the individual.
Describe organised offenders
- Show evidence of having planned the crime in advance; the victim is deliberately targeted and will often reflect that the offender has a ‘type’
- Maintain a high degree of control during the crime with almost detached surgical precision.
- Little evidence left behind at the crime scene. Tend to be of above-average intelligence, in a skilled profession.
- Social and sexually competent, they are usually married with kids.
Describe disorganised offenders
- Show little evidence of planning; suggests offence was spontaneous, spur of the moment act.
- Crime scene tends to reflect the impulsive nature of the attack - body is still at the scene and there appears to have been very little control during the crime.
- Tend to have a lower than average IQ and be in unskilled work or unemployed.
- Often have a history of sexual dysfunction and failed relationships. Tend to live alone, relatively close to the site of offence.
How is an FBI profile constructed?
- Data assimilation - the profiler reviews the evidence (e.g. Crime scene photographs)
- Crime scene classification - organised or disorganised
- Crime reconstruction - hypotheses made, in terms of sequence of events, behaviour of victim, etc…
- Profile generation - hypotheses are related to the likely offender, e.g. Their demographic background.
Evaluate the top-down approach
- Only applied to particular crimes - crime scene must reveal important details about the suspect, only possible in rape, arson, etc…More common offences such as burglary, it cannot be applied to. Therefore a limiting approach.
- Based on outdated models of personality - typology classification assumes that offenders behaviour remains consistent across all situations and contexts. Alison et al suggested that this approach only sees behaviour driven by stable dispositional traits, rather than external factors.
- Contradicting evidence for disorganised offender - Canter et al used smallest space analysis to analyse data from 100 murders in the USA. Case details examined with reference to 39 expected characteristics of killers, yet findings only proved a distinct organised type.
Describe the bottom-up approach
- The British model. Profilers work up from evidence collected from the crime scene to develop hypotheses about the likely offender, e.g. Routine behaviour.
- Unlike the top-down approach, it doesn’t begin with fixed typologies, instead the profile is ‘data-driven’ using systematic analysis of the crime scene.
- Investigative psychology is used as well as geographical profiling.
Describe investigative psychology
- A form of bottom-up profiling that matches details from the crime scene with statistical analysis of typical offender behaviour patters. This acts as a ‘baseline’ for comparison.
- Once matched it can reveal important details about the offender (e.g. Family background). This can also determine if a series of offences are related or not.
- Central to the approach is interpersonal coherence - the way an offender behaves at the scene may reflect their behaviour in everyday situations. This could inform the profiler of the offenders daily interactions with others.
- The significance of time and place, as in geographical profiling, may indicate where the offender lives.
- Forensic awareness describes those who have experienced police interrogation before, so are mindful in covering their tracks.
Describe geographical profiling
- First described by Rossmo in 1997, uses information of the location of linked crime scenes to make interferences about the likely home of the offender - know as ‘crime mapping’.
- Can be used in conjunction with psychological theory to create hypotheses about the offenders modus operandi.
- Assumes that serial offenders will restrict crimes to familiar geographical areas, so understanding the spatial pattern can provide a ‘centre of gravity’ which the investigators can use to predict where the next crime will be - jeopardy surface.
- Canter’s circle theory proposed two models of offender behaviour: the marauder (operates in close proximity to their home base) and the commuter (travelled a distance from their usual residence). Such spatial consistency can offer insight, e.g. The offenders usual mode of transport
Evaluate the bottom-up approach
- Evidence to support the investigative psychology - Canter and Heritage conducted a content analysis of 66 sexual assault cases. Using smallest space analysis, several characteristics were identified as common in offending behaviour, e.g. The use of impersonal language. This shows the usefulness as it can be applied.
- Evidence to support geographical profiling - Lundrigan and Canter collated information from 120 murder cases involving serial killers in the USA. Smallest space analysis revealed spatial consistency in the behaviour of the killers, with the offenders base located in the centre of the pattern. The effect was most noticeable for the marauder type model.
- Studies examining the effectiveness of offender profiling have produced mixed results - Copson surveyed 48 police forces and found that the advice provided by the profiler was ‘useful’ 83% of cases but in only 3% did lead to accurate identification.
What is smallest space analysis?
A statistical technique which identified correlations screeds patterns of behaviour.
Why is the bottom up approach seen as more beneficial, compared to the top-down approach?
- Bottom-up approach has more scientific basis than the top-down approach - Canter’s argument is that it’s more objective as it’s grounded in evidence. With the aid of advanced AI, investigators are able to manipulate geographical, biographical and psychological data quickly to produce insights.
- Bottom-up approach had a much wider application to many more other offences. Smallest space analysis can be used in the investigation of crimes such as burglary, as well as more serious offences such as rape.
Describe the atavistic form as a biological explanation
- A historical approach to offending, proposed by Lombroso, that attributes criminal activity to a lack of evolutionary development.
- Offenders are viewed as genetic throwbacks, who are biologically different from non-criminals. Such individuals are distinguished by particular facial and cranial characteristics.
- Atavistic characteristics - narrow/sloping brow, strong jaw, high cheekbones, facial asymmetry, dark skin and existence of extra toes, nipples or fingers. Murderers - bloodshot eyes, curly hair and long ears. Sexual deviants - glinting eyes, swollen/fleshy lips and projecting ears.
- Other aspects - insensitivity to pain, use of criminal slang, tattoos and unemployment.
- Lombroso’s research: examined Italian convicts - 383 dead criminals and 3839 living ones, concluding that 40% of criminal acts could be accounted for by atavistic characteristics.
Evaluate the atavistic form
- Contradictory evidence - Goring attempted to replicate Lombroso’s findings by comparing 3000 criminals with 3000 non-criminals, concluded there was no significant differences between the two groups. However, he did suggest that many offenders have lower than average intelligence.
- Scientific racism - DeLisi drew attention to the racial undertones within Lombroso’s research (e.g. Darkskin and curly hair) which is found amongst the African descent. Contributes to eugenic philosophies, even though it may not have been intended.
- ‘Father of modern criminology’ - contributed to criminology by shifting the emphasis in crime research away from moralistic discourse and towards a more scientific/credible realm.
- Correlation is not causation - facial and cranial differences may be influenced by other factors such as poverty/diet. In his later work, Lombroso realised criminals can be made as well as born.
What is the genetic explanation of offending behaviour? (Biological explanation)
- Genetic explanations for crime suggests that offenders inherit a gene/combination of genes, that predispose them to commit crime - this is illustrated by twin studies.
- Lange (1930) investigated 13 identical and 17 non-identical twins, where one of the twins had served time in prison. Lange found that 10 of the identical twins and only 2 of the non-identical twins had a co-twin who was also in prison.
- Similarly, Christiansen (1977) studied 87 MZ and 147 DZ pairs and found a concordance of 33% for MZs and 12% for DZs.
- A genetic analysis of almost 900 offenders by Tiihonen et al (2014) revealed abnormalities on two candidate genes, which may be associated with violent crime: The MAOA gene controls dopamine and serotonin in the brain and has been linked with aggressive behaviour. CDH13 has been linked to substance abuse and attention deficit disorder.
- Diathesis-stress model: genetic predisposition triggered by biological/psychological factors, e.g. Being raised by a criminal parent.
What is the neural explanation of offending behaviour? (Biological explanation)
- Neural explanations for crime suggests there may be neural differences between the brains of criminals and non-criminals, in terms of activity of brain structures and neurotransmitters.
- Raine conducted many studies of the APD brain (antisocial personality disorder - characterises many convicted criminals), and reported that APD individuals have reduced activity in the prefrontal cortex (regulated emotional behaviour).
- Raine et al (2000) found an 11% reduction in the volume of grey matter in the prefrontal cortex of people with APD, compared to controls.
Evaluate the biological explanation of offending behaviour
- Problems with twin studies used to explain crime as genetic - Lange’s research was poorly controlled and judgements related to zygosity were based on appearance rather than DNA testing. Small sample size cannot be generalised, also twins are reared in the same environment (confounding variable affecting concordance rates). Lacks validity.
- Supporting evidence for diathesis-stress model of crime - Mednick et al (1984) conducted a major study of over 13,000 Danish adoptees. Found when neither the biological nor adoptive parents had at least one conviction, the percentage of adoptees that did was 13.5%, this rose to 20% when either parents had convictions, and 24.5% when both biological and adoptive parents had convictions.
- Criminality is complex, explanations that reduce offending behaviour to a biological level may be too simplistic. Even though there is often a difference in concordance rates between MZ and DZ twins, MZ pairs do not show 100% concordance. Reductionism.
Outline Eysenck’s theory as a psychological explanation
General personality theory - Eysenck (1947) proposed that behaviour could be represented along two dimensions: introversion/extraversion (E) and neuroticism/stability (N). Later added psychoticism (P) as the third dimension, all combine to form a variety of personality traits.
- Biological basis
- The criminal personality
- The role of socialisation
- Measuring the criminal personality