Forensics Flashcards
Crime
Violates the law, usually has a punishment, such as prison. Can be defined as any act that breaks the law and therefore warrants some form of punishment.
Official statistics
Government records of the total number of crimes reported to and recorded by the police. This allows the government to develop crime prevention strategies and also direct resources to those areas in need.
Victim survey
A questionnaire that asks a random sample of people which crimes have been committed against them over a fixed period of time. Whether or not they’ve been recorded to the police.
Offender survey
A self report measure that requires people to record the number and types of crime they have committed over a specific period.
Problems in defining crime
Cultural and historical issues.
Cultural issues in defining crime
What is considered a crime in one culture may not be one in another. Eg polygamy and forced marriage is illegal in the UK but in other cultures it’s still practiced.
Historical issues in defining crime
Definitions of crime change over time. Eg. Homosexuality was considered a crime until 1967.
Ways of measuring crime
Official statistics.
Victim surveys.
Offender surveys.
Evaluation- official statistics
Unreliable- underestimate the true extent of crime. So many crimes go unreported by victims or unrecorded by police. Meaning that only around 25% of crimes are included in the official statistics.
Farrington and Dowds- police in the borough of Nottinghamshire more likely to record theft under £10. Which explained a spike of crime. This suggests that policing priorities may distort official figures.
Evaluation- victim surveys
More accurate, as crimes that may have not been reported to the police are included. However it may have distorted figures from having to remember past crimes over a long duration ‘telescoping’
Evaluation- offender surveys
Provide insight into how many people are responsible for certain offences. However it may be unreliable as offenders may want to conceal serious crimes or may over exaggerate for bravado. However the targeted nature of the survey means that certain types of crime such as burglary are over represented, where as middle class crime such as fraud are unlikely to be included.
Offender profiling- the top down approach
Offender profiling is an investigative tool employed by the police when solving crimes. The top down approach originated in the US and offender profilers who use this method will match what is known about the crime and the offender to a pre existing template that the FBI developed, then classified in the organised or disorganised.
Offender profiling- the top down approach- organised types of offender
Organised offenders- show evidence of having planned the crime in advance, the victim is deliberately targeted. There is little evidence or clues left behind at the scene. They tend to be of above average intelligence, in a skilled professional occupation, They also tend to be married and socially and sexually competent.
Offender profiling- the top down approach- disorganised types of offender
Disorganised offenders- show little evidence of planning suggesting it may have been spontaneous. They tend to have a lower than average IQ, be in unskilled work or unemployed. Often have a history of sexual dysfunction and failed relationships. Usually live alone and live close to the place of offence.
Offender profiling- the top down approach- Constructing an FBI profile
There are 4 main stages in the construction of an FBI profile: Data assimilation (profiler reviews evidence), Crime scene classification (organised or disorganised), Crime reconstruction (hypothesis in terms of sequence of events/behaviour of victim), Profile generation (hypothesis related to the likely offender).
Offender profiling - the top down approach- evaluation
Only applies to crime scenes that reveal important details about the suspect, such as rape. However, it doesn’t work for common offences such as burglary because the crime scene reveals very little about the offender.
Based of the assumption that offenders have patterns of behaviour that remain constant across situations and contexts. Not always true.
Canter- analysed data from 100 murders in the US, supported the organised type but not the disorganised type, however its still used and has widespread support.
Offender profiling- the bottom up approach.
(UK) Aim to generate a picture of the offender, their likely characteristics, routine behaviour and social background through systematic analysis of evidence at the crime scene. The profile is data driven and more emerges with deeper details.
Offender profiling- the bottom up approach- investigative psychology
Aim to establish patterns of behaviour that are likely to occur across crime scenes. This is then made into a database that then acts as baseline for comparison. This helps to see if a series of crimes are done by the same person. The significance of time and place is a key variable and also how they ‘interact’ with the victim. May be sorry or want to humiliate them.
Offender profiling- the bottom up approach- geographical profiling
Uses information to do with the location of linked crime scenes to make inferences about the likely home or base of an offender, known as crime mapping. Their thinking is that serial offenders will restricts their work to areas that they’re familiar with. It may help investigators make educated guesses where the next strike will be.
Canter’s circle theory said that someone who works close to their home base is a marauder and someone who has traveled a distance away is a commuter. It usually creates a circle, from which they can see if it was planned , mode of transport and approximate age.
Offender profiling- the bottom up approach- evaluation
Canter conducted a content analysis of 66 sexual assault cases, the programme used identified several characteristics in common. This can lead to an understanding of how an offenders behaviour may change over a series of offences.
Spatial information was key in determining the base of an offender.
More grounded in evidence and psychological theory, also less driven by speculation and hunches compared to the top down approach.
Biological explanations- Atavistic form
Lombroso suggested that criminals were genetic throwbacks- biologically different from non criminals. Lombroso saw offenders as lacking evolutionary development, and that their savage and untamed nature meant that they would find it impossible to adjust to the demands of a civilised society and would turn to crime.
Biological explanations- Atavistic form characteristics
Narrow sloping brow, a strong prominent jaw, high cheekbones, facial asymmetry, dark skin, extra toes/fingers/nipples.
Murderers have bloodshot eyes, curly hair and long ears.
Sexual deviation- glinting eyes, swollen fleshy lips and projecting ears.
Fraudsters- thin reedy lips.
Biological explanations- Atavistic form- Lombroso’s research
Lombroso examined the facial features of hundreds of Italian convicts, both living and dead. (3839 living and 383 dead). He concluded that 40% of criminal acts could be accounted for by atavistic characteristics.
Biological explanations- Atavistic form- evaluation
Lombroso shifted emphasis onto evolutionary influences and genetics rather than them being judged as wicked and weak minded.
Scientific racism- Many features that Lombroso identifies are most likely to be found among people of African descent (curly hair, dark skin).
Contradictory evidence- Goring did a similar study between 3000 criminals and 3000 non criminals, found no evidence that they have unusual facial features but found that criminals have lower than average IQ.
Biological explanations- Genetic explanations- Lange
Lange- investigated 13 MZ twins and 17 DZ twins where one of the twins in each pair had served time in prison. He found that 10 MZ twins but only 2 DZ twins had a co twin who was also in prison. He concluded that genetic factors must play a prominent part in offending behaviour.
Christiansen also found similar results; MZ twins had a 33% concordance rate and DZ twins had a 12% concordance
Biological explanations- Genetic explanations- candidate genes
Candidate genes- Tiihonen found abnormalities on 2 genes that may be associated with violent crimes such as MAOA the warrior gene and CDH13.
Biological explanations- Genetic explanations- diathesis stress model
A tendency towards criminal behaviour may come about through the combination of genetic predisposition and biological or psychological trigger. For example, being raised in a dysfunctional environment having criminal role models.
Biological explanations- Neural explanations
Evidence suggests there may be neural differences in the brains of criminals and non criminals. Antisocial personality disorder have reduced emotional response and a lack of empathy for the feelings of others.
Biological explanations- Neural explanations- Prefrontal cortex
Raine conducted many studies of the APD brain. reporting that there are several dozen brain imaging studies demonstrating that individuals with APD have reduced activity in the prefrontal cortex. Also found 11% reduction in the volume of grey matter in the prefrontal cortex.
Biological explanations- Neural explanations- Mirror neurons
Keysers found that only when criminals were asked to emphasise from a person feeling pain on a film, did their empathy reaction by mirror neurons activate. This suggests that APD individuals are not totally without sympathy but may have a neural switch that can be turned off and on.
Biological explanations- Genetic explanations- Evaluation- Twin studies.
Lange’s twin studies were poorly controlled and were identified as MZ or DZ twins by appearance and not genetics. Twin studies also include small sample size which may not be generalizable to the rest of the population. Twins are also raised in the same environment so it is a major confounding variable as concordance rates may be due to shared learning experiences not genetics.
Biological explanations- Genetic explanations- evaluation- support for the diathesis stress model
Mednick studied over 13,000 Danish adoptees. The researchers defined criminal behavior by being in possession of at least one court conviction and this was checked amongst each adoptee’s police records. When neither of the adoptees biological or adoptive parents had no convictions. The adoptees that did were 13.5%. This raised to 20% when either of the parents had a conviction and to 24.4% when both parents had convictions.
Biological explanations- Genetic explanations- evaluation- biological reductionism
Criminality is complex, reducing it to genetic or neural level may be inappropriate and overly simplistic. Whilst there is differences between concordance rates between MZ and DZ twins, but MZ twins don’t show 100% concordance.