forensics - P3

defining and measuring crime - AO1

• any act that violates the law and results in punishment by the state. deemed wrong by the state and the law.

ways of measuring crime:

official statistics:

• Home Office - police reports - make historical comparisons to look at trends in crime.

victim surveys:

• ask a sample of people to identify which crimes have been committed against them over a fixed period of time - CSEW - Crime Survey for England and Wales - repeated every year, around 50,000 households aged 16 and over.

• sample selected randomly - high ecological validity.

• fixed set of questions relating to general attitudes - all confidential.

offender surveys:

• OCJS - Offending, Crime and Justice Survey - increase knowledge about young people and offending behaviour - produce information about the extent of offending, antisocial behaviour and drug use.

defining and measuring crime - AO3

1. defining crime - some behaviours regarded as universally unacceptable - rape, murder. cultural variations - French concept where a sentence should be more lenient if the crime was done impulsively and unplanned.

2. official statistics - doesn’t include the dark figure of crime - the ones that don’t get reported to the police - walker - 42% of crime reported in the victim survey were reported to the police - CA - generate trends that mirror society.

3. victim surveys - provides information about the dark figure of crime - depends on the honesty of the answers - more consistent when making comparisons across time and making trends - CA - only 75% of those contacted took part - biased sample.

4. offender surveys - self-report method - lack of accuracy - underplay their criminal involvement.

offender profiling - top-down approach - AO1

• used in the US by the FBI.

• profiler has a feel for the type of person who committed the crime.

stages of the approach:

• profiling inputs - description of crime scene, background info on victim, details of crime - weapon, cause of death.

• decision process models - organises the data into meaningful patterns

  • murder types - single, mass, spree.

  • time - how much type the murder took, at night or day.

  • location - was the crime scene, like a kidnapping, near the murder scene.

• crime assessment:

  • organised - planned crime with targeted victim and hidden weapon - offenders high in intelligence, socially and sexually competent and follows crimes in the media.

  • disorganised - unplanned, random victim, engage very little with victim, many clues left at scene.

• criminal profile - construct a profile with a hypothesis about the likely beliefs and habits of the offender - work out a strategy to help catch the offender.

• crime assessment - written report given to the investigating agency and people matching the profile are evaluated.

• apprehension - suspect apprehended, process reviewed to see that the conclusions that were made at each stage were legitimate.

Åoffender profiling - top-down approach - AO3

1. usefulness - Copson questioned 184 US police officers, 82% said the technique was useful and over 90% said they would use it again. may not result in identification of suspect but it investigates multiple perspectives and opens up new avenues for investigation to prevent wrongful convictions.

2. flawed methodology - the basis of the method came from interviews with 36 of the most dangerous and sexually motivated murderers, which helped identify the key characteristics that would help the police read the crime scene - such individuals aren’t likely to be the best source for this information and their rationale may vary quite a bit from more typical offenders - CA, improvements can constantly be made with the process.

3. There is difficulty in distinguishing between organised and disorganised offenders. Turvey suggests that the dichotomy is false as it is likely to be a continuum rather than 2 distinct categories. One solution could be including a third category called the ‘mixed’ offender which would seem to lessen the usefulness of the classification because there is now a kind of dustbin category. Canter found that the classification has little basis in reality - they analysed 39 aspects of serial killings in murders committed by 100 US serial killers. Their analysis revealed no clear division between organised and disorganised offenders - there were subsets of organised types crimes and little evidence for disorganised crimes.

Offender profiling - bottom-up approach - AO1

Investigative psychology: David Canter profiling should be based on psychological theory and research:

• interpersonal coherence - people are consistent with behaviour so there will be links over time with the crime and everyday life - behaviour changes over time, so looking over a lengthy period will offer more clues.

• Forensic awareness - people might have an awareness of police techniques - rapists who conceal fingerprints often had a previous conviction for burglary.

• Smallest space analysis - statistical technique - 3 underlying themes found in co-occurrence of 48 crime scenes with offender characteristics taken away where victim was a stranger:

  • instrumental opportunistic - using murder to accomplish a goal and taking the easiest opportunities to do so.

  • Instrumental cognitive - concern about being detected so more planned.

  • Expressive impulsive - uncontrolled, hat of emotion, maybe provoked by the victim.

Geographical profiling:

• analysing locations of a connected series of crimes and considering where the crimes were committed, the spatial relations between the crimes and how they might relate to a offenders place of residence.

• Circle theory - marauder, home within geographical area that crimes is committed - commuter, offender travels to another space to commit the crime.

• Criminal geographical targeting - Rossmo - 3-D map displaying spatial data related to time, distance and movement to and from crime scene - called a jeopardy surface - different colours indicate likely closeness to crime scene.

Offender profiling - bottom-up - AO3

1. Usefulness of the method - Copson surveyed 48 UK police forces and found that over 75% said the advice was useful, however, only 3% said the advice helped them catch the offender - nevertheless, most said they would us a profiler again - only used in 75 cases a year.

2. Success of geographical profiling - Rossmo - may not solve crimes specifically, can help prioritise house-to house checks and identifying a geographical area where DNA can be collected - cannot distinguish between multiple offenders within the same area and it is limited to spatial behaviour rather than personality - Rossmo implemented the approach in Vancouver, but shortly after his dismissal, they ceased to use it because they said it didn’t enhance policing outcomes.

3. Scientific basis of the approach - more scientific than the top-down because of the objective statistical techniques - such techniques are only as good as the data that is put in and the underlying assumptions used to work out the links between items - the data used is related to offenders who have already been caught, doesn’t tell us about the behaviour patterns related to unsolved crimes. Although the approach has the potential to be systematic and objective, it is inevitably biased in practice.

Biological explanations - historical approach - Lombrosso - AO1

• atavistic form - certian individuals born with a criminal personality and this innate personality is a throwback to earlier primate form.

  • high cheekbones

  • Large forehead

  • Long arms

  • Curly hair.

• Empirical differences - post mortem examinations of 3839 dead people and 383 alive convicts - tested their skulls - 21% had one atavistic feature and 43% had at least 5.

• Environmental influences - inherited atavistic form combined with a persons physical and social environment - deterministic because it says that factors outside a persons control determine whether they become criminal:

  • born criminals - atavistic types - throwbacks to ancestry.

  • Insane criminals - mental illness

  • Criminaloids - mental characteristics predispose them to criminal behaviour under the right circumstances.

• Somatotypes:

  • athletic - tall and muscular - violent.

  • Pyknic - short and fat - deception and violent crimes.

Biological explanations - historical approach - Lombrosso - AO3

1. Criticised methodology - lack of adequate controls - Goring compared 3000 convicts with a group of non-convicts - no difference, except the convicts were slightly smaller.

2. Gender bias - believed women were less evolved than men and naturally jealous and insensitive to pain, also passive and low in intelligence - neutralised eg active traits and so less likely to be criminals - the women who became criminals had masculine characteristics with benefited a man but made a woman a monster - androcentrism.

3. Links between genetics and environment - people with features described as atavistic might be more likely to lean towards criminal behaviour due to the way that they are treated. Self derogation argues that if individuals experience persistently poor interactions with others, they will develop lower self esteem and increased frustration, making it more likely to commit crime. Known as the interactionist approach, arguing there is an interactions between biological aspects of offenders appearance and the way they are treated, leading to offending behaviour.

Biological explanations - genetic and neural - AO1

genetic explanations:

• Raine - 52% concordance with MZ and 21% DZ twins.

• MAOA - Brunner found that male members of a Dutch family who were prone to violence and criminality shared a particular gene that had abnormally low levels of MAOA.

• CDH-13 - Finnish study found that low activity related to offenders.

• Diathesis stress - epigenetics are a material in each cell of the body that act like set of switches to turn genes on and off - epigenomes turn off and on genes based which have been affected by the environment - possibility is maltreatment.

Neural explanations:

- regions of the brain

• prefrontal cortex - Raine studies 71 brain imaging scans and murderers, psychopaths have reduced functioning in the prefrontal cortex, involved in regulating emotion and moral behaviour - lowered activity linked to impulsiveness and loss of control.

• Limbic system - set of subcortical structures like the thalamus and amygdala linked to emotion and motivation - Raine studies murdered who were found not guilty by reason of sanity and compared with matched controls they found that there were abnormal asymmetries in the limbic system of the murderers, especially the amygdala - reduced activity on the left and increased on the right

Neurotransmitter:

• Serotonin - low levels predispose people to impulsive aggression.

• Noradrenaline - very high and very low associated with aggression violence and criminality. - helps perceive threats, low levels reduce this ability. High levels associated with fight or flight - and aggression.

Biological explanations - genetic and neural - AO3

genetic:

1. Support from adoption studies - Crowe - adapted children with a biological parent with a criminal records had a 50% greater risk of having a criminal record by 18, whereas adopted children whose mother didn’t have a criminal record only had 5% risk.

2. Most research focuses on links to violent behaviour and criminality, but doesn’t explain others like theft or fraud - others argue that crime is a social construction - people created the category of criminal behaviour - cat explain just with genetics and environmental interaction.

Neural:

1. Real world applications - low levels of serotonin - high level in diets in prisons.