Forensics

• Offender profiling: characteristics of an offender can be deduced from the offence and the particulars of the crime scene. The aim is to narrow down the field of inquiry and the list of likely suspects. This involves careful scrutiny of the crime scene and analysis of evidence, allowing hypotheses to be generated about the probable characteristics of the offender
• The top-down approach uses pre-existing templates. This method originated in the US from the FBI's behavioural science unit, drawing upon data gathered from interviews with 36 sexually motivated killers. This method involves matching what is known about the crime and offender to a pre-existing template that the FBI developed. Murderers and rapists are classified into two categories: organised and disorganised. These categories are based on the idea that serial offenders have signature 'ways of working' or MOs (modus operandi)
• One famous MO is that of Ted Bundy, who pretended to have a broken arm to appear vulnerable, and then beat victims to death with a blunt object.
• Organised offenders:

  1. Plan the crimes in advance
  2. Show high degrees of control
  3. May show detached, surgical precision
  4. Little evidence is left behind
  5. Above-average intelligence
  6. Victim is deliberately targeted (they have a 'type')
  7. Have a professional occupation
  8. Socially and sexually competent
  9. Often are socio/psychopaths
• Disorganised offenders:

  1. Lack of plan ('spur of the moment')
  2. Lack of control at the crime scene i.e. overkill
  3. Body left at the scene, clues or evidence left behind
  4. The victim is not targeted, opportunistic
  5. Low intelligence
  6. Socially and sexually incompetent
  7. Poor employment history
  8. Little interest in their crimes after
• • Top-down profiling is best suited to crime scenes that reveal important details about the suspect, such as rape, arson and cult killing, as well as crimes that involve such macabre practices and sadistic torture, dissection of the body and acting out fantasies.
  • More common offences such as burglary and destruction of property (or even murder or assault) do not lend themselves to profiling because the resulting crime scene reveals very little about the offender
  • LIMITATION – This means that, at best, it is a limited approach to identifying a criminal.
• • The top-down approach is based on the assumption that offenders have patterns of behaviour and motivations that remain consistent across situations and contexts.
  • Several critics (e.g. Alison et al., 2002) 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. LIMITATION – This means the top-down approach has poor validity when it comes to identifying possible suspects and/or trying to predict their next move.
• Canter analysed data from 100 US murders. Details of each case were examined with reference to 39 typical organised and disorganised killer characteristics. Although the findings suggested evidence of a distinct organised type, this wasn't the case for disorganised - undermining the classification system as a whole. – The fact that disorganised offenders cannot be identified as distinctly different from organised offenders suggests that this system lacks validity and breadth. + The organised/disorganised distinction is still used by profilers in the US and has widespread support.
• Behaviours that describe organised and disorganised types aren't mutually exclusive. Godwin asks how police would classify a killer with high intelligence + sexual competence who commits a spontaneous murder + leaves the body. Other researchers have also proposed more detailed typological models. Holmes suggests there are 4 types of serial killers: visionary, mission, hedonistic and power; Keppel & Walter focus on motivations killers have rather than trying to determine specific types. L– the top-down approach is oversimplified.
• The typology approach was developed using interviews with 36 killers in the US. Critics have pointed out that this is a small, unrepresentative sample upon which to base a typology system that has a significant influence on the police system and investigation. Canter argued that it's not sensible to rely on self-report data with convicted killers when constructing a classification system. L- This approach is based on a restricted sample of 36 killers which means findings can't be generalised to a wide population. The use of self-report means that findings can't be relied on for validity.
• The Bottom-Up approach is data-driven. It was developed in the UK by David Canter and is thought to be more scientific than the Top-Down approach. The aim is still to generate a picture of the offender, their likely characteristics, routine behaviour and social background, through the analysis of evidence at the crime scene. This approach makes no assumptions about the person you're dealing with. Instead, a profiler will gather all the information and then build a logical description based on that.
• Investigative psychology allows profilers to see whether a series of crimes have been committed by the same person. Patterns of behaviour that occur across crime scenes help build a statistical database. Specific details of an offence are then matched to the database to reveal important details about the offender.
• Interpersonal coherence refers to the fact that the way an offender behaves at the crime scene may reflect their behaviour in everyday situations
•  “Criminals are performing actions that are direct reflections of the sorts of transactions they have with other people.” 

  • David Canter (1994)
• Geographical profiling uses the location of crimes to determine the likely home/operational base of an offender (A.K.A crime mapping). The offender's base is often found in the middle of an area where the offending took place. Canter believed there were two types of offender: The Marauder- operates in a close proximity to their home base, and The Commuter- likely to have travelled a distance away from their usual residence
• The assumption os that serial killers operate in geographical areas they are familiar with, and so understanding the spatial pattern of behaviour provides investigators with a 'centre of gravity' which is likely to include the offender's base.
• Canter & Heritage (1990) conducted a content analysis of 66 sexual assault cases, data was examined using smallest space analysis – a program identifying correlations across patterns of behaviour. Several characteristics were identified as common in most cases, e.g. the use of impersonal language + lack of reaction to the victim. These characteristics occur in different patterns in different individuals. This can lead to an understanding of how an offender’s behaviour may change over time, or in linking offences to an offender. +Use of statistical techniques elevates scientific credibility.
• • Lundrigan and Canter (2001) collated information from 120 murder cases involving serial killers in the USA.
  • Smallest space analysis revealed spatial consistency in the behaviour of the killers: The location of each body disposal site was in a different direction from the previous, creating a ‘centre of gravity’; the offender’s base was invariably located in the centre of the pattern.
  • The effect was more noticeable for offenders who travelled short distances (marauders). SUPPORT – This supports Canter’s claim that spatial information is a key factor in determining the base of an offender.
• Bottom-up profiling is more objective and scientific than the top-down approach as it's more evidence-based. With the aid of AI, investigators can manipulate geographical, biographical and psychological data to produce insights and results that assist the investigation. Investigative Psychology has expanded to include areas like suspect interviewing and examination of material presented in court, which supports its utility in all aspects of the judicial process. SUPPORT – This is more scientific and based on psychological theory compared to the top-down approach, which is over-simplistic.  
• • Another advantage the bottom-up approach has over its US rival is that it can be applied to a wide range of offences.
  • Techniques such as smallest space analysis and the principle of spatial consistency can be used in the investigation of crimes such as burglary and theft as well as more serious offences such as murder and rape. SUPPORT – The bottom-up approach can be applied to a wide range of offences, unlike the top-down approach. 
• Despite the success of the bottom-up approach, there have been significant failures and studies examining offender profiling effectiveness have produced mixed results. Copson surveyed 48 police forces, finding that advice provided by profilers was judged as ‘useful’ in 83% of cases, but in only 3% it led to accurate offender identification. Kocsis et al. found that chemistry students produced a more accurate offender profile on a solver murder case than experienced senior detectives. L – This approach is a useful profiling method, but doesn't always lead to correct offender identification.
• • In 1876, Cesare Lombroso, an Italian physician wrote a book called ‘The Criminal Man’ in which he suggested that criminals were ‘genetic throwbacks’ - a primitive subspecies who were biologically different from non-criminals
  • Although Lombroso’s theory of the atavistic form would be best described as speculative and naïve today, he is credited as moving criminology into a more rigorous and scientific realm, and his ideas may well have laid the foundation for the modern offender profiling techniques that were to follow.
• • Lombroso saw offenders as lacking evolutionary development - their savage and untamed nature meant they would not adjust to the demands of civilised society and would eventually turn to crime
  • As such, Lombroso saw criminal behaviour as a natural tendency, rooted in their genetic makeup (genealogy) i.e. they are a born criminal.
  • Lombroso argued, the criminal sub-type could be identified as possessing particular physiological ‘markers’ there were linked to particular types of crime.
• These are biologically determined ‘atavistic’ characteristics, mainly features of the face and head:

  • Narrow, sloping brow
  • Strong jaw
  • High cheekbones
  • Facial asymmetry

  Other physical markers included dark skin, extra toes, nipples and fingers.
• • Murderers were described as having bloodshot eyes with a cold glassy stare, curly hair and long ears.  
  • Thieves have expressive faces, are good with their hands and have small wandering eyes.
  • Sexual deviants as having glinting eyes, swollen lips and protruding ears.  
  • Female criminals are short, have dark hair, small skulls and are wrinkled.
  • Many criminals will be tattooed and will speak using a strange form of slang
• The work of Francis Galton in the 1880s is generally cited as the beginning of the Eugenics Movement. Galton was heavily influenced by Darwin, whose concept of ‘survival of the fittest’ became the cornerstone of eugenics philosophy.

  Galton’s basic argument was that not all people in society are born equal. Desirable human traits, such as intelligence, morality and civility, are inherited and found in some social and cultural groups more than others. Those groups with a genetic advantage should be allowed to breed for the good of society, whilst those without should be eliminated.
• Lombroso has been hailed the ‘father of modern criminology’ (Hollin) and is credited with shifting the emphasis in crime research away from a moralistic discourse (where offenders were judged as being wicked and weak-minded) towards a more scientific and credible realm (that of evolutionary influence and genetics). Also, in trying to describe how particular types of people are likely to commit particular types of crime, Lombroso’s theory, in many ways, heralded the beginning of criminal profiling.+ In this way, Lombroso made a major contribution to the science of criminology.
• Several critics, including DeLisi, have drawn attention to the distinct racist undertones of Lombroso’s work. Many features that Lombroso identified as criminal and atavistic, (e.g. curly hair and dark skin) are most likely to be found among people of African descent. Similarly, his description of the atavistic being ‘uncivilised, primitive, savage’ lends support to many of the eugenics philosophies of the time. Whether Lombroso intended this to be the case or not; it's an uncomfortable + controversial aspect of his legacy which overshadows his theory. – racist undertones, bad credibility.
• Goring (1913), set out to establish if there were any physical or mental abnormalities among the criminal classes. After comparing 3000 criminals and 3000 non-criminals he concluded there was no evidence that offenders are a distinct group with unusual facial and cranial characteristics (though he did suggest that many people who commit crimes have lower-than-average intelligence). – Whilst the point about intelligence offers some limited support to Lombroso’s argument that criminals are ‘sub-species’, it questions the key element of his theory that criminals are different appearance-wise.
• Unlike Goring, Lombroso did not compare his criminal sample with a non-criminal control group. It is possible that had he done so, the significant differences in atavistic form that Lombroso also failed to account for other important variables within his research. Many of the criminals he studied had suffered from a history of psychological disorders which may have confounded the findings. LIMITATION – The internal validity of Lombroso’s research was compromised therefore findings and conclusions must be interpreted with caution. 
• Although Lombroso suggested criminals have atavistic facial features, this doesn’t prove these traits cause offending. Factors like poverty or poor diet may influence physical differences rather than evolutionary delay. Lombroso later acknowledged environmental factors play a role, recognizing criminals could be "made" as well as "born." His deterministic view, linking physical traits to crime, overlooks free will and moral values, limiting its usefulness in explaining individual differences.
• Genetic explanations - twin studies:

  1. Lange 1930 looked at 13 MZ and 17 DZ twins where one of each pair had served time in prison. Lange found that 10 of the MZ twins but only 2 of the DZ twins had a co-twin who was also in prison (and concluded that genetic factors must play a predominant part in offending behaviour)
  2. Christiansen 1977 studied 87 MZ and 147 DZ pairs and found a concordance rate of 33% for MZs and 12% for DZs. However, these are still low percentages, therefore there is a big gap that is unaccounted for by the data.
• Genetic explanations - candidate genes:

  A genetic analysis of 900 Finnish offenders by Tiihonen et al. (2014) revealed abnormalities in two genes that may be associated with violent crime:

  1. The MAOA gene - controls dopamine and serotonin in the brain + has been linked to aggressive behaviour
  2. The CDH13 gene has been linked to substance abuse and attention deficit disorder
  3. Within the Finnish sample, individuals with this high-risk combination were 13 times more likely to have a history of violent behaviour. However, this research is in its early stages and has not been replicated.
• Diathesis-stress model:

  if genetics do have some influence on offending, it seems likely that this is at least partly moderated by the effects of the environment. A tendency towards criminal behaviour likely comes about via the combination of genetic predisposition and environmental triggers e.g. being raised in an abusive household.
• Neural explanations

  Evidence suggests that there may be neural differences in the brains of criminals and non-criminals. Much of the evidence in this area has investigated individuals diagnosed with antisocial personality disorder or APD (formerly known as psychopathy). APD is associated with reduced emotional responses, and a lack of empathy for others, and is a condition that categories criminal behaviour.
• Neural explanations

  The Prefrontal Cortex - Adrian Raine has conducted many studies of the brain of those with antisocial personality disorder, reporting there are several dozen brain-imaging studies demonstrating that individuals with antisocial personalities have reduced activity in the PFC, the part that regulates emotional behaviour. Alongside this, Raine et al. (2000) found an 11% reduction in the volume of grey matter in the PFC of people with APD compared to controls.
• Neural explanations - mirror neurones:

  recent research suggests that criminals with APD can experience empathy but they do so more sporadically than the rest of us. Keysers et al (2011) found that only when criminals were asked to empathise with a person depicted in a film as experiencing pain did their empathy reaction (controlled by mirror neurones in the brain) activate. This suggests that individuals with APD aren't completely without empathy, but may have a neural 'switch' that can be turned on and off, unlike the 'normal' brain that has the empathy 'switch' permanently 'on'.
• Early twin studies of criminality, such as Langeʼs research, were poorly controlled + judgements related to zygosity (that is whether twin pairs were MZ or DZ) were based on appearance rather than DNA testing, so lack validity. Also, twin studies typically involve small sample sizes; and twins are not a representative sample. Finally, the fact that most twins are reared in the same environment is a major confounding variable as concordance rates may be due to shared learning experiences rather than genetics. – suggests causal conclusions about the genetic basis of criminality may be invalid.
• A major study of over 13,000 Danish adoptees were conducted by Mednick et al. (1984) in which the researchers defined criminal behaviour as being in possession of at least one court conviction and this was checked against Danish police records for each adoptee. When neither the biological nor adoptive parents had convictions, the percentage of adoptees that did was 13.5%, this figure rose to 24.5% when both adoptive and biological parents had convictions. + The data suggests that although genetic inheritance plays an important role in offending, environmental influences can’t be disregarded.
• Adoption studies assume a separation of genetic and environmental factors, but this is complicated by late adoption, where children might spend much of their early years with biological parents, and by ongoing contact with them post-adoption. Additionally, the Mednick et al. study's findings on petty offences, like burglary, may not apply to violent crimes, making it hard to draw conclusions about the environmental impact of biological parents based on adoption studies alone.