Lesson 2: Bottom-up approach to offender profiling Flashcards
Where was the bottom up approach developed?
In the United Kingdom
What is the bottom up approach?
this approach aims to develop an image of the offender, their characteristics, routine behaviours, living area and social background through the systematic analysis of the crime scene
Differences between the top down and bottom up approaches
The bottom up approach does not begin with fixed typologies like the top down approach does (disorganised/organised)
The profile is data driven and emerges from the rigorous scrutiny of evidence. More grounded in psychological and scientific theory than the top down approach
Investigative psychology
Aims to establish a statistical database of behaviours which occur at a crime scene and the characteristics of offenders who would carry out these behaviours
- Specific details of an offence can then be matched against this database, revealing statistically probably details of an offender based on the crime scenes.
Key to investigative psychology is the idea of interpersonal coherence, the significance of time and place, and forensic awareness
Interpersonal coherence
The way a criminal behaves at a crime scene is similar to how they behave in their everyday life. For example, rapists who want to control or humiliate their victims may behave to women in a generally similar way, while others may be apologetic, and behave in a similar way in their everyday life
The significance of time and place
Details of where and when the crime occurred also gives us an idea of where the criminal lives, and may give us an idea of their method of travel
Forensic awareness
Criminals may have made attempts to ‘cover their tracks’ like hiding a body or cleaning the crime scene. This could indicate that they have been subject to police interrogation before and have experience in committing crimes. The police may already have their DNA, so they may already be aware of the suspect
Geographical profiling
Study of the spatial behaviour of a criminal. The location of a crime may be a clue as to where the criminal lives, works or socialises. The assumption is that a serious offender will restrict their activities to an area that they are familiar with. Therefore, the offenders’ ‘base’ will be in the middle of the spatial pattern of their crime scenes.
Canter and Larkin (1993)
Proposed two models of offender behaviour
- The marauder (operates close to their home)
- The commuter (travels a distance away from their home)
The spatial pattern of their crime scenes will still form a circle around their home. This becomes more apparent the more offences are committed.
Strengths of the top down approach
- Canter argues that the bottom up profile is more scientific than the top down approach because it is more grounded in psychological evidence and theory. It is less driven on speculation like the top down approach
- The bottom up approach can be applied to a wider range of offences unlike the top down approach, such as burglary and theft as well as serious offences.
Weaknesses of the bottom up approach
- Real life failures, like the stabbing of Rachel Nickell in 1992. She was a 21 year old woman who was stabbed 47 times and was sexually assaulted in a frenzied attack on Wimbledon Common. In 2008, Robert Napper was convicted of murder, after previously being rules out because he was several inches taller than the profile.
- Copson (1995) surveyed 48 police forces and found that the advice provided by a profiler was judged to be useful in 83% of cases, but in only 3% of cases did it lead to accurate identification of an offender. It does not have a great success rate.
- Kocsis et al (2002) found that chemistry students were able to produce a more accurate offender profile than experienced senior detectives. You could argue that this approach is little more than common sense or guess work
