forensics Flashcards
what is the top down approach to profiling?
-broad approach used by FBI
-looks carefully at crime scene and draws conclusions from the evidence about the offender.
-by interviewing criminals profilers could build a picture of typical offender behaviours and build a profile from the top down.
who made a distinction between organised and disorganised offenders?
-Hazelwood and Douglas 1980
-highlighted diff characteristics for each
what are the differences between organised and unorganised offenders?
-organised: planned, victim targeted, weapon absent from scene, body is removed or hidden in crime scene.
-unorganised: unplanned, victim not targeted and unplanned violence.
what are the stages of top down profiling?
-Jackson and Bekerian 1997
-stage 1: Data assimilation, collection of all evidence available.
-stage 2: crime classification, organising crime into a particular type e.g organised or unorganised.
-stage 3: crime reconstruction, reconstruct the crime scene in order to develop predictions about the motives and behaviour of the offender.
-stage 4: profile generation, developing a profile based o information regarding various characteristics.
what is the first stage of top down profiling?
-stage 1: Data assimilation, collection of all evidence available.
what is the second stage of top down profiling?
-stage 2: crime classification, organising crime into a particular type e.g organised or unorganised.
what is the third stage of top down profiling?
-stage 3: crime reconstruction, reconstruct the crime scene in order to develop predictions about the motives and behaviour of the offender.
what is the fourth stage of top down profiling?
-stage 4: profile generation, developing a profile based o information regarding various characteristics.
who studied the accuracy of the organised and disorganised offender types?
-Canter et Al
-conducted content analysis on 100 cases of serial killers in the US and used criteria set out by Douglas to classify and disorganised and organised.
-found significantly more disorganised crimes and further analysis of types of crime did not clearly separate the organised and disorganised crimes
evaluation of top-down approach to profiling?
-out of 184 police officers 82% said it was useful and 90% would use it again.
-sample problems, classification based on 36 interviews with most dangerous murders found highly manipulative and not likely to give reliable info.
-not applicable to all crimes like stealing, destruction of property.
-difficult to distinguish between organised and disorganised crime
what is the bottom up approach to offender profiling?
-makes use of past data on similar crimes committed in order to build a picture of the offender.
-use different principles to build up picture of offender
why did Canter develop a way of the bottom up approach?
-partially motivated by a desire to see offender profiles built up on objective data rather than an intuition approach
what are the principles of the bottom up approach?
-time and place, will communicate something about their own place of residency or employment.
-interpersonal coherence, consistency between the way that offenders interact with their victims and with others in their everyday lives.
-criminal characteristics, characteristics about the offender can help to classify them which helps the police investigation.
-forensic awareness, offenders who show an understanding of a police investigation are likely to have had previous encounters with the criminal justice system.
what is the atavistic form?
-Lombroso believed that criminals were individuals who had failed to evolve at the same pace as everyone else and could be identified by their characteristics.
what features characterise the atavistic form?
-18 different.
-large jaw
-high cheekbones
-large chin
-insensitivity to pain
-hard shifty eyes
what did Lombroso research?
-gathered info from autopsies of dead criminals and studied the faces of living criminals.
-over career studied 50,000
-21% of convicts had only one atavistic feature while 43% had at least 5
what three types of criminals did Lombroso believe there were?
-born criminals,
-insane criminals
-criminaloids, large proportion who were predisposed towards crime under the right environment.
what are the three different body types Lombroso believed?
-Endomorphic, fat and soft tend to be sociable and relaxed, even tempered and easy to get along with.
-ectomorphic, thin and fragile, introverted and restrained self conscious and afraid of people.
-mesomorphic, muscular and hard, tend to be aggressive and adventurous, seek vigorous physical activity, most likely to offend.
strengths of Lombroso?
-shifted the emphasis away from moralistic discourse towards a more scientific and credible realm of evolutionary influences and genetics, in many ways marked the beginning of criminal profiling.
weaknesses of Lombroso?
-obvious racial undertones by atavistic features.
-correlation does not imply causation and facial and cranial differences may be influenced by other factors like poor diet rather than being an indication of delayed evolutionary development.
-Gowing 1913 compared 3000 criminals and 3000 non criminals and concluded no evidence for offenders being a distinct group.
-Lombroso himself didn’t have a control group and sample may have had individuals with learning difficulties which may have effected criminals features anyway.
what does the genetic explanation process for offending?
-one or more genes which criminals inherit predisposes them for criminality.
how were twin studies used for genetic explanation?
-Raine 1953 reviewed a large range of research studies on the delinquent behaviour of twins and found that for MZ twins concordance rates were 52% and for DZ 21%
what gene predisposes you to criminality?
-Monoamine oxidase MAOA
-CDH13
what does the MAOA gene do?
-controls production of dopamine and serotonin which have been linked to increased aggression
what research into genes of criminals?
-Tiihonen et al 2014 analysed genetic make up of 900 criminals.
-findings reveal that offenders were 13% more likely to have a violent offending past with CDH13 and MAOA genes.
what is the diathesis-stress model?
-is a biopsychosocial model which says that even though genes will likely play a role in the development of criminality they are likely to be meditated by environmental factors.
-although criminals may have a tendency towards criminality they need to be placed in stressful environment to commit the behaviour.
what are epigenetics?
-proposes that genes are switched on or off by environmental factors.
what did Capsi et al research?
-2002
-found that 12% of those men with low MAOA genes had also experienced maltreatment when they were babies.