Forensic

• Offender profiling

  The top-down approach: Assumptions about the characteristics of an offender are made by careful analysis of the offense they commit
• Modus operandi


  • A crime is not random, offenders have a very distinctive way that they commit their crimes
• Types of offenders


  • Organized
  • Disorganized
• Organized offenders


  Plan their crime, prepare by bringing weapons and restraints, tidy the crime scene, hide the body, reflect an average or higher than average intelligence
• Disorganized offenders


  Don't plan their crime in advance, use weapons found at the crime scene, leave messy crime scenes, don't try to hide the body, reflect a below average intelligence
• Ressler in 1986 created definitions of organized and disorganized offenders using interviews with real serial offenders, classified 24 as organized and 12 as disorganized
• Snook in 2007 found major crime officers agreed that criminal profiling helps solve cases 94% and is a valuable investigative tool 88.2%
• Canter in 2004 reviewed 100 U.S. serial killers, found disorganized features were rare and didn't form a distinct type, suggesting a false dichotomy between the two types and that organization is typical of most serial killers
• Offender profiling - bottom-up approach

  An evidence-based approach using statistical analysis of data collected at the crime scene and information such as choice of victim and location, also referred to as investigative psychology
• Factors in the bottom-up approach

  • Interpersonal coherence
  • Interactions while the same in personal life
  • Time and place significance
  • Criminal characteristics
  • Criminal career
• Geographical profiling


  A branch of investigative psychology focused on where an offender is likely to be based, not on personal characteristics, assumes the location of crime is not random and helps investigators narrow down search areas
• Least effort principle


  The closest suitable crime scene to the criminal's home base is picked, meaning fewer crimes further away
• Distance decay


  Crimes radiate out from the home base creating a circle
• Types of offenders


  • Marauders
  • Commuters
• Canter and Larkin in 1993 found 87% of 45 British serial sexual assaulters were marauders, supporting the circle hypothesis and the idea that the choice of place of crime is a significant factor in offender behavior
• Bottom-up profiling makes inferences based on statistical analysis from published research, so it's seen as more scientific than top-down which relies on the intuition and experience of individual criminal profilers
• Both top-down and bottom-up profiling methods suffer from the problem of statistically abnormal offenders, whose behavior wouldn't match what would be expected
• Biological explanations - Lombroso's atavistic form


  Criminals genetically are at a more primitive stage of human evolution than non-criminals, so criminality is innate and criminals are born not made
• Physical differences of criminals

  • Asymmetrical faces
  • Heavy brows
  • Very small or big ears that stick out
  • Large jaws
  • Excessively long arms
• Goring in 1913 compared biological measurements of 3,000 criminals with 3,000 non-criminals and found no physical differences when controlling for factors like age, class, and intelligence
• Atavistic form is an example of scientific racism, claiming biological features such as dark skin identified criminality, influencing racist policies of eugenics and biased IQ testing that harmed black communities
• Attitude form might confuse cause and effect, where people with certain physical features are rejected by society and turn to crime, creating a criminal stereotype that becomes a self-fulfilling prophecy
• Genetic explanations


  Inherited genotypes make the display of criminal behavior (the phenotype) more likely
• Genetic factors linked to criminality

  • Short variant MAO gene producing less MAO
  • Interaction between genes and environment, e.g. child abuse and MAO
• A meta-analysis of 51 twin adoption studies found that genetics accounted for 41% of the variants in antisocial behavior, and environmental effects 59%
• A case study on a family in the Netherlands found that 5 males with a defective MAO gene had a history of impulsive aggression, suggesting extreme levels of criminality can have a genetic origin
• A study found people with antisocial personality disorder had an 11% reduction in prefrontal gray matter compared to people without the disorder, suggesting a neurological basis
• Eysenck's theory of the criminal personality

  Criminal personality is due to the type of nervous system we inherit, influencing arousal and behavior
• Eysenck's personality dimensions


  • Extrovert to introvert
  • Neurotic to stable
  • Psychoticism
• McGurk and Dougall in 1981 found a higher number of people with extrovert, neurotic, and psychotic personality types in a delinquent group compared to a control group
• Moffitt's dual taxonomy suggests a distinction between life course persistent offenders and adolescent limited offenders, better explaining offending figures
• Cognitive explanations


  Suggest there are ways of thinking and internal mental processes about the world and moral decisions that lead to offending behavior
• Cognitive distortions


  Failures of the mind in accurately representing reality that can lead to criminal behavior, e.g. hostile attribution bias and minimalization
• Holland and Palmer in 1998 found male offenders showed poor moral reasoning compared to male non-offenders, suggesting offenders have developmental moral deficits
• Kolberg's theory of moral development is limited by the use of hypothetical dilemma tasks and social desirability bias, reducing its generalizability to real-life offenses
• Other people's internal mental states are biased assuming negative intentions
• Minimalization


  Interpreting our own behavior as less serious than it really is, for example denying our actions caused harm
• Holland and Palmer in 1998 found male offenders showed poor and moral reasoning on 10 of the 11 questions on moral reasoning compared to male non-offenders
• This suggests offenders do have developmental moral deficits
• Understanding the link between offending behavior and cognitive processing means controversial therapy could be used to change offenders' rational thinking