Forensics Flashcards
What is offender profiling?
A behavioural and analytical tool that it intended to help profilers accurately predict and profile the characteristics of unkown offenders. It may be used to help people narrow down a list of subjects. Will involve careful analysis of the crime scene and anaylsis of other evidence in order to generate hypotheses about the probable characteristics of the offender
What is the top-down approach?
Created in America. Gathered data from in-depth interviews with 36 sex offenders and concluded that they could be organised into categories of organised ansd disorginised murderers. Each category had certain characteristics which meant that the data collected from a crime scene matched an offender than we could predict other characteristics, therefore profiling them
Describe an organised offender
Show evidence of having their crime planned in advance. The victim is targeted and they have a type of victim. The offender maintains a high degree of control during the crime and may operate with surgical precsision. There is little evidence left at the crime scene. They tend to be above average intelligence, a skilled job and are a socially competent
Describe a disorganised offender
They show little evidence of planning and it suggests their attacks may be a ‘spur of the moment’. The body is left at the scene and there is little control from the offender. They tend to have a lower than average intelligence and are unemployed. They tend to live alone and close to a crime
What are the stages of constructing an FBI profile?
Data assimilation - The profiler reviews the evidence
Crime scene classification - organised or disorganised
Crime reconstruction- - hyptheses in terms of sequence of event, victim behaviour etc
Profile generator
Evaluate the top down approach
One strength is that there is RESEARCH SUPPORT for an organised offender. Canter et al conducted an analysis of 100 US murders conducted by different serial killers. Smallest space analysis was used as they assessed 39 aspects of serial killings i.e. whether there is torture or restraint, a weapon etc. This anlysis revealed there is subset of features that match typology
Counterpoint: Many suggest they are not mutually exclusive. There are a variety of combinations given at a crime scene. A killer may have multiple characteristics so it may be more of a continuum
Evaluate the top down approach
Another strength of top down profiling is that it can be adapted to other crimes. Meketa et al has suggested that top down profiling has been recently applied to burlgary leading to a 85% rise in solved burglaries in three states. The detection method adds to more categories inetrpersonal and oppurtunistic. This suggests top down profling has a wider effect than assumed
Evaluate the top down approach
One limitation is the evidence on which it is based. Canter et al has argued that the sample on which the study was based is poor and it did not include different types of offender and there was no standard set of questions so each interview was different. This therefore suggests offender profling does not have a sound scientific base
Describe the bottom up approach
Developed in the UK. It refers to a data driven profile in which evidence is collected from the crime scene to build up of profile of the criminal. It involves a more rigourous scrutiny of the crime scene in comparison to using fixed typologies
Describe investigative psychology
It is an attempt to apply staistical procedures and theory to analysis of a crime scene. The aim is to establish patterns which can be used to develop a statistical database which is used as a baseline. It is matched against this database to establish a profile
What are some of the key variables in investigative psychology?
Interpersonal coherence- How they act with the victim. For example some rapists want to gain control whereas others are mroe apologetic
Significance of time and place- Where they live
Forensic awareness- whether they have been involved in a crime before and are able to cover up their evidence
Describe geographical profiling
Uses information about the location of crimes to make links to where the offender is living/where their base is (crime mapping). It is based on spatial consistency which suggests offenders work in geographical locations. Assumption is that they will work in geographical location they are familar with
Describe Canters circle theory
The pattern of offending forms a circle around the offenders operational base. We can describe an offender in one of two ways
Marauder- close proximity
Commuter- travel a distance away
Can offer important insight into the nature of the crime i.e. whether it was planned or not
Evaluate the bottom up approach
One strength is that there is research support. Canter and heritage studies a group of 66 sexual offences using small space analysis. Several behaviours such as impersonal speech were consistent and each person displayed a characteristic pattern of behaviour to establish whether two or more offences were by the same person
Counterpoint: Case linkage will only be based on historical crimes in the database and they were only solved due to this linkage, creating a circular argument
Evaluate the bottom up approach
Another strength is there is research evidence for georgraphical profiling. Lundigran and Canter studies 120 serial killers in the US and found that each person had a centre of gravity as each time they disposed of a body they went in a different direction. This meant their house was found
Evaluate the bottom up approach
One limitation is geographic profiling may not be sufficient on its own. May be reliant on the quality of data provided. Crime reports are not always accurate and only 75% of crimes are reported to the police. Other factors are also just as important in creating an approach. This suggests it does not always lead to a successful capture
Describe Lombroso’s hisorical/biological approach
Suggests criminals were genetic throwbacks and were biologically different from non-criminals. Offenders were lacking evolutionary development meaning they turn to crime. He suggested crime was rooted in the genes of those who partook suggesting it was innate
Describe the avatistic form
Offender subtypes could be marked by specific facial characteristics etc. These features include: high cheekbones, prominent jaw, dark skin, extra fingers or toes. he also suggested other features such as tattoos and slang could link to this
Describe Lombroso’s offender types
Murderes had bloodshot eyes, curly hair and long ears
Sexual deviants had glinting eyes, swollen lips and projecting ears
Fraudsters had thin lips
Describe lombrosos research
Studies 363 dead convicts and 3839 living ones and found 40% of acts are found by people with the avatistic form
Evaluate lombroso
One strength is that it has changed the face of the study of crime. He has been hailed the father of modern criminology as he shifted it away from a moralistic perspective and towards a more scientific perspective. He also is heralded as starting offender profiling.
Counterpoint: Critics has suggested his work isn’t entirely positive. many have highlights racist undertones as many features of the avatistic form (curly hair, dark skin) are common for those of african descent. This fitted into the eugenic attitudes of the 19 century
Evaluate lombroso
One limitation is evidence contradicts the link between avatism and crime. Goring carried out a study of 3000 offenders and 3000 non-offenders and found that there was no evolutuonary difference between the two. This therefore challenges the idea that offenders can be physically distinguished
Evaluate lombroso
Another limitation is his methods were poorly controlled. Lombroso did not compare his sample of offenders with a control group which leads to a high level of confounding variables i.e. there has been links between crime and poverty. This suggests his research does not meet modern scientific standards
What are genetics?
Genetics refer to DNA and how physical features such as eye colour or size of brain structures are passed down from person to person. It may also impact psychological traits
Describe a twin study showing offending rates
Christiansen studied over 3500 twin pairs in Denmark and found that that offending behaviour concordance rates for MZ male twins were 35% whereas for DZ male twins it was 13%. This incuded all twins born between 1880 and 1910 and data was compared to Danish offending rates
Describe candidate genes
A genetic analysis of almost 800 Finnish offenders found there are two main genes that cause offences: MAOA and CDH13.
MAOA is linked to serotonin control and has been linked to violent crime
CDH13 is linked to substance abuse and ADHD
Analysis found that 5-10% of all violent crime in finland is a result of this
Describe the Diathesis stress model
A tendency towards offending behaviour may come through a combination of a genetic predisposition and a psychological event
Evaluate genetic explanations for offending
One limitation is the assumption of equal environments. It is assumed by researchers that the environment were kept constant and while this may be the case for MZ twins as they look similar so people treat them the same, this may not be the case for DZ twins. This means concordance rates for MZ may be highers as they are treated more similarly
Evaluate genetic explanations for offending
One strength is there is support for the D-S model. A study of 13,000 danish offenders shows that when no parent had committed a crime, 13.5% of adoptees committed crime. however this rises to 20% is the bio parents had and 24.% is both sets had. This shows both genetic and environment has influence on genes
What is the neural explanation for offending behaviour?
Behaviour is caused by dysfunction in the brain and nervous system. There is differences in offenders that have been associated with APD whic results in lack of empathy etc
Describe the prefrontal cortex role in offending behaviour
Several brain scan studies show people with APD have reduced activity in the prefrontal cortex, the part of the brain that regulates emotions. They found a 11% decrease in grey matter
Describe mirror neurons
They may show empathy but differently. Found that when asked to empathise with someone they were able to do this. This is a result of mirror neurons which suggest that they may have an empathy switch they can turn off and on
Evaluate neural explanations
One strength is there is research support. Reviewed evidence of damage and found that those with damage tend to show impulsive behaviour and emotional instability. Shows brain damage may have an effect
Evaluate neural explanations
One limitation is that it is complex. Study of offenders that scored highly on this shows that they has other risk factors as a child such as neglect. It could be that this alongisde the neural differences could have caused it. Suggests the relationship is complex
