What is Profiling?
Ainsworth (2001) described profiling as a process of using all available information about a crime to compose a profile of the unknown perpetrator.
It's used to narrow down suspects.
US top-down approach
Aims to identify criminals
Predict future acts by..
- Looking at different types of criminal behaviours and motivation.
- Using intuitive analysis of data based on personal experience in the law enforcement
- Matching a particular type of crime to the features of that crime.
1979- FBI came up with two ways to distinguish 36 serial killers
- Organised murderers (have average intelligence, plan their crimes and remove evidence)
- Disorganised murderers (have low intelligence, commit spontaneous crimes and leave evidence)
Also classified ****
- Anger- excitement
Process of catching offender
When a crime is committed
- available data from sources is collected
- evidence is used to catagories the crime
- hypothesis are developed about what the offender/victim did
- profile on the offender is developed.
Top-down approach used.
He was a serial killer.
Profiling didn't get him caught but it did comfirm it was him as accurate profiling matched his personality, lifestyle etc...
Whey 'top down'?
It assumes crimes are classfied into clear types.
The profile generation is driven from 'above'.
Holmes- studied 192 cases of prfiling and found that in 17% of cases prfilinf helped with arrests.
Douglas- in 77% of cases profiling helps.
Data was based on 36 serial killers and so they were...
Likely to lie or exaggerate about the nature of their crime.
Sample collected was too small and so likely to be unrepresentative.
Interview method was non-standardised and so results cannot be compaired because it was not reliable or constant.
Weaknesses and Strengths
One weakness is that it's unscientific as developments of offenders types was done throught intuition.
However, this could be a strength as investigators could draw on their years of first hand experience.
Validaty question when Canter et al (2004) found no distinction between organised and disorganised murderers when analysing 100 murderers.
Holmes and Holmes ammended the classification system:
British bottom-up approach
Focuses on data driven building up a more individualistic profile.
The use of statistical analysis
Finding associations between criminals
Difference from American approach
The British approach is based more on science than intuition.
A victim group can be used, while data analysis helps to identify patterns of behaviour.
Behaviour at the crime scene may suggest if the offender has forensic awareness.
For example, Davis et al (1997) found that rapists who try and conceal their finger prints also have convictions for burglary.
The Small Space Analysis and why 'bottom up'?
It can identify the most useful crime scene evidence.
It is called the 'bottom up' approach because it focuses on pecing together a profile from the crime scene information. It does not look for patterns of behaviour but it is more evidence driven.
Used in the case of John Duffy
Police recorded that he had no children, he was in his late 20's and was right handed.
This information led to his arrest.
Britton (1992)- sent questionnairs to CID chiefs and found profiles didn't contribute to arrests.
Copson (1995)- sent questionnairs to police officers and found that 80% of profile information was useful.
Key assumption that criminals with similar clemographic characteristics show similar crime scene behaviour.
Mokros and Alison (2002)- found no significant correlation in characteristics of rapists.
Bottom- up approach looks at each crime individually, so each profile is unique and tailored to available evidence = more accurate way of securing data.
Many investigators say this method to profiling significantly contributed to solving crimes.
Conclusion of Approaches to Profiling
Both methods have limited use.
Copson and Holloway (1997)- in some cases where profiling is used you'd be better of tossing a coin (not useful).
Harrower (1998)- profiling has potential.
When used properly, offender profiling leads to quicker identification of criminals which helps to develop interrogation techniques, hopefully leading to a confession of guilt.
Both methods of profiling have benefited from high profiling techniques, which often get reported in the press.