Forensics - top-down approach

Question 1

offender profiling

Answer 1

help to identify who committed a crime

Question 2

where did the top down approach originate

Answer 2

US

Question 3

how did the top down approach originate

Answer 3

in 70s, analysed data from in-depth interviews of 36 sexually motivated killers. concluded data could be divided into two categories: top-down and bottom-up

Question 4

what are the categories used for

Answer 4

each has different categories and characteristics seen at the crime scene can be matched to a category then other characteristics of offender can be predicted

Question 5

modus operandi

Answer 5

a particular way/method of doing something. offenders have one and it correlates with characteristics

Question 6

two categories of offenders

Answer 6

organised and disorganised

Question 7

characteristics of organised offenders

Answer 7

• evidence of advanced planning
• victims deliberately targeted
• high degree of control and precision
• little evidence left
• above average IQ
• skilled profession
• seems socially competent

Question 8

characteristics of disorganised offenders

Answer 8

• little evidence of planning
• little control evident at crime scene
• clues and evidence often left
• lower than average IQ
• unskilled work/unemployed
• tend to live alone and close to crime scene
• history of failed relationships and sexual dysfunction

Question 9

top down approach to offender profiling

Answer 9

focuses on behaviour and expects it to stay consistent

Question 10

4 steps of how the FBI construct a profile

Answer 10

1. data assimilation - review evidence
2. crime scene classification - disorganised or organised
3. crime reconstruction - generate hypothesis of sequence of events and behaviour of offender and victim
4. profile generation - hypothesis is related to likely offender characteristics

Question 11

strengths of the top down approach

Answer 11

+ support for organised category by Canter. analysed 100 murders by different serial killers. statistical test showed subset of features matched the FBI’s typography for organised offenders
+ wider applications for crimes like burglary. Meketa found 85% burglary cases are solved in 3 US states. additional categories can be added like interpersonal and opportunistic
+ 94% Canadian detectives agreed profiling helped their work

Question 12

limitations of top down approach

Answer 12

• organised and disorganised categories are not mutually exclusive, some offenders have contrasting characteristics. maybe typography is more of a continuum
• flawed evidence base (based on 36 serial sex offenders). not selected randomly, not a variety of killers, no standardised procedure
• only evidence for organised serial killer - characteristic of serial killers
• based on self report from serial offenders
• never used in isolation so difficult to assess helpfulness