forensics Flashcards
Outline top-down
Linked to American ‘typology approach’ as start by looking at types of offender
Crime fitted to pre-existing templates; organised or disorganised, based on interviews conducted by Hazelwood & Douglas, or as was later added ‘mixed’
4 stages in analysis:
Data assimilation (gather police/pathology reports & photos)
Crime scene classification (organised or disorganised)
Crime reconstruction (hypothesise behaviours and crime sequence)
Profile generation (present hypotheses: demography, physical characteristics & behavioural habits)
Organised crime scene characteristics
Victim is a stranger, use of restraints, rape, uses a vehicle, little or no evidence (semen etc.), hidden body.
Organised offender personality/behaviours
Socially competent, intelligent, planner, living with a partner, follows the crime in the media, may return to the crime scene and anticipates police questioning, above average intelligence.
Disorganised crime scene characteristics
Victim known to killer, crime spontaneous, sloppy crime scene, evidence present.
Disorganised offender personality/behaviours
Socially immature, sexually inhibited, harsh childhood discipline, lives alone, knows victim, shows no interest in the media and does not change their lifestyle as a result of the killing. Below average IQ.
Evaluate top-down
1) based on interviews with 36 sex offenders by Hazelwood & Douglas, 49% were categorised as having superior or very superior intelligence so would have been able to deceive or embellish info which reduces validity. Also not very generalisable as only 36 and all sex offenders, doesn’t account for other types of crime
2) – Canter et al (2004) wanted to test the validity of the organised/disorganised distinction with a different and larger sample. Canter used a content analysis on information from 100 murders by 100 different serial killers in America and looked for characteristics typical of either organised or disorganised offenders. Overall he concluded that all serial murders have an organised element to them and therefore the category base that the top down approach is based on is invalid. Canter suggests that it would be better to study the individual personality differences between offenders than the organised and disorganised elements to their crimes
3) According to Holmes (1998) the top-down approach has contributed to arrest in only 17% of the cases in which it was used. Although this is low, it could still be regarded as a valuable contribution as the cases it is used for are usually high profile and prove a high risk to members of the public. Therefore, any contribution and saving of lives is valuable
Outline bottom-up approach
3 main factors:
1. Significance of time and place (Time and location of crime will communicate something about where the offender lives/works)
2. Interpersonal Coherence (A consistency about how the offender interacts with their victims and with others in their everyday life
3. Forensic awareness (If they have been subject to police enquiry before, or how mindful they are of covering their tracks.)
2 parts:
1. Investigative psychology (looks for consistencies between crimes and interactions with others to make predictions about offender characteristics, starts with details then looks at bigger picture, uses statistical database to compare and match offenders to crimes) and
2. Geographical profiling (use a computer system to map out the locations of crimes and use circle theory to work out the home/work/location of the serial offender - this will usually be central to the area distribution of crimes because the benefits of knowing an area outweighs risk of recognition. Most offenders will either be a “marauder” (likes to commit crimes in own neighbourhood) or a “commuter” (travels to commit crimes but still within a defined area.)
Evaluate Bottom Up Approach
- Copson (1995) gave questionnaire to detectives who had used offender profiling (184 instances.) Only 16% of the profiles were directly acted upon and only in 3% of these did it lead to identification of the offender. Hoever 83% of the respondents said the advice was useful and 61% said it had furthered their understanding of the case/offender.
- The Railway Rapist - Canter created a profile that was accurate in 13/17 points including where the killer lived, that he was unhappily married and was childless. When they ran this through the database a match came up for John Duffy who had already been arrested and released due to refusal to give a blood test - and he was the offender.
- It’s scientific and objective as it is database driven. Therefore less biased by opinion. However, it relies on an accurate and powerful database - which sometimes isn’t the case.
Compare Top-Down and Bottom-Up Approaches
- Bottom-Up is more objective. Less risk of interpretation errors by both profilers and police
- Both approaches share weaknesses. Both Top-Down and Investigative Psychology can only be used in very serious violent crimes.
- However, Bottom-Up has geographical profiling as well which can be used in other types of crimes
- Canter prefers bottom-up as less driven only by 2 types which were derived from only a limited small sample (36 interviews of sex offenders)
Historical biological explanation of offending
Atavistic form - Lombroso theory that criminals were a less evolved sub-species that you could measure by physical traits such as a protruding jaw, drooping eyes or sloping shoulders as well as other factors like greater pain threshold or lack of moral sense which results in lack of remorse and more cruelty.
Genes so some individuals pre-disposed to crime
Anger management
Method for reducing criminal behaviour
Therapy that identifies offender’s aggressive behaviour and triggers teaches alternative coping mechanisms, eg. meditation techniques
Custodial sentencing
Method for reducing criminal behaviour
Punishment for crime via sentencing for either prison or another institute for holding them
Differential association
Criminal behaviour develops through experiences and association with other criminal behaviour
Eysenck’s theory
Criminal behaviour result of personality traits, eg. high extraversion and neuroticism
Hostile attribution bias
Type of cognitive distortion to explain criminal behaviour
When someone interprets other people’s behaviour as hostile even when it isn’t, eg. misinterpreting someone’s neutral face as angry/aggressive
