Forensic download

• Crime


  Any illegal act which is punishable by incarceration or another type of punishment, after consideration by a judge and jury in a legal trial
• There exist historical and cultural issues with defining 'crime'
• Historical issues with defining crime

  • What was considered a crime at one point in history, may not be considered a crime according to modern standards (e.g. homosexuality only being legalised in the UK in 1967)
• Cultural issues with defining crime

  • Smacking a child in one culture may be seen as acceptable or even encouraged as a form of 'tough love', whereas this is not the case in the UK - smacking a child so that a mark is left is now punishable by law, according to the 2004 Child's Protection Act
• Methods of measuring crime


  • Official Statistics
  • Victim Surveys
  • Offender Surveys
• Official Statistics


  The number of crimes reported to and recorded by the police, which have been processed and published by the Home Office on an annual basis
• Victim Surveys


  50,000 randomly selected households self-report the number and types of crimes which have been committed against them during the past year, and is published by the Crime Survey for England and Wales annually
• Offender Surveys


  A randomly-selected cohort of criminals give details of the types and frequency of crimes they have committed across a set time period (e.g. during the last year), as recorded by The Offender Crime and Justice Survey
• Official statistics are susceptible to concealing the 'dark figure' of crime (where 75% of crime goes unreported)
• Sudden increases in incidence rates of theft could be explained by a change in police recording policies, where thefts under £10 were recorded, showing official statistics are distorted by police priorities
• Victim surveys may suffer from 'telescoping', where the victim may mistakenly believe that a crime had been committed against them significantly more recently than it actually had been, due to the trauma and distress associated with it
• Data collected from Offender Surveys may be distorted or biased because it has been collected from offenders who may want to over-exaggerate or under-exaggerate their crimes
• Top-down approach to offender profiling


  Uses a pre-established typology and the FBI method of profile generation to assign offenders to one of two categories: organised or disorganised offenders
• Profile generation (top-down approach)

  1. Data assimilation

  2. Crime reconstruction

  3. Crime scene classification

  4. Profile generation
• Organised offenders


  • Socially and sexually competent, showing evidence of planning and so are unlikely to leave the body or clues at the crime scene, tend to have a specific 'type' of victim, and appear to carry out the attack in an almost surgical manner
• Disorganised offenders


  • Have the opposite characteristics to organised offenders, showing no evidence of planning and so frequently leave the body and clues at the crime scene, their attacks appear to be random, with no specific target and more likely to occur close to their own home or operational base, they are socially and sexually incompetent, often living alone and being unemployed
• The top-down approach can only be used to explain crimes where there have obvious, visible characteristics (e.g. rape and sadistic murder) and so are unlikely to be effective in identifying criminals who are responsible for burglary or middle-class crimes, such as financial fraud
• It is unlikely that all offenders are able to be identified as either organised or disorganised
• There is evidence to support the existence of an organised offender type, but the same cannot be said for the disorganised type
• Bottom-up approach to offender profiling

  Uses no pre-established typology but develops a profile as the crime scene and eyewitness testimonies are increasingly analysed, the two hallmarks are investigative psychology and geographical profiling
• Investigative psychology


  The process whereby each crime is recorded onto a database, then the details of each new crime are matched with this database in order to develop hypotheses about the likely characteristics, social demographic and motivations of the culprit
• Geographical profiling


  Suggests that each offender has an operational base, which can be inferred through mapping the locations of previous crimes, this should form a circular shape, where the operational base or 'centre of gravity' is at the centre, and can also be used to predict future crimes through the analysis of a jeopardy surface
• Information from an offender profile only led to the successful identification of the offender in 3% of cases, but was useful 83% of the time
• Many supporting studies have used the method of smallest space analysis to establish correlations between two variables or offender characteristics in the bottom-up approach
• Following the smallest space analysis of 120 serial murder cases, researchers were able to identify characteristic traits of spatial consistency, such as the presence of a jeopardy surface and the centre of gravity
• Atavistic form theory


  The historical approach to offender profiling proposed by Lombroso, suggesting that criminals were 'genetic throwbacks' who were not accustomed to the social norms of normal, civilised society and so in this sense were more suited for crime, criminals could be identified by signature atavistic characteristics
• Atavistic characteristics


  • Long ears, dark skin, extra toes and nipples, and curly hair
• Atavistic characteristics associated with certain crimes

  Murderers had bloodshot eyes, fraudsters had reedy lips, whilst sexual deviants had glinting eyes
• Lombroso's atavistic form theory has been branded as racist by many modern researchers
• Lombroso's methodology did not use statistical analysis or a control group from another culture, so the findings lack scientific rigour
• Lombroso may be considered as 'the father of criminology', as his methods of attributing certain atavistic or cranial features to certain types of criminals with specific traits, was the basis from which modern criminal profiling was developed
• Genetic explanations of offending


  Focus on the heritability and role of candidate genes in the development of criminal behaviour
• Christiansen et al (1977) found concordance rates of 33% for identical (87 MZ) twins but only 12% concordance for non-identical (147 DZ) twins, suggesting a moderate genetic or heritable basis of criminal behaviour
• The concordance rates for MZ twins is not 100%, suggesting an interaction between the environment and genetics together produces the outcome of criminality
• Candidate genes


  Slight genetic variations which increase the risk of developing criminal behaviour, such as abnormalities in the MAOA and CDH-13 genes which code for neurotransmitters like serotonin and dopamine
• Neural explanations of offending


  Focus on individuals with antisocial personality disorder (APD), a disorder which is very common amongst criminals
• Criminals have a lower volume and activity level (11% reduction) in the prefrontal cortex, which is responsible for logical thinking and decision making
• Criminals appear to have a 'neural switch' which they can use to turn their capacities for empathy on or off
• Twin studies assume the only difference between twins is their genetics, but this may not be the case
• Neural explanations for criminality

  • Focus on individuals with antisocial personality disorder (APD)
  • Criminals have a lower volume and activity level (11% reduction) in the prefrontal cortex, which is responsible for logical thinking and decision making
  • Criminals appear to have a 'neural switch' which they can use to turn their capacities for empathy on or off