Lesson 2: Bottom-up Approach To Offender Profiling

Question 1

What is the bottom-up approach?

Answer 1

• Developed in the UK, aim is to generate a picture of the offender, including their likely characteristics, routine behaviour and social background. This is achieved through systematic analysis of evidence left at the crime scene. The bottom-up approach does not begin with fixed typologies, instead the profile is data-driven and emerged as the profiler engages in rigorous scrutiny of the details of the offence. Bottom-up profiling is more grounded in psychological theory than the top-down approach.

Question 2

What is investigative psychology?

Answer 2

• Aim is to establish behaviours that are likely to occur at certain crime scenes. This is done in order to create a statistical database which then acts as a baseline for comparison. Specific details of an offence can then be matched against this data base in order to reveal statistically probable details about the offender (their personal history, family, background etc.). This can help determine whether multiple offences are linked and likely to be committed by the same individual.

Question 3

What is interpersonal coherence?

Answer 3

• Interpersonal coherence is central to investigative psychology. The way in which an offender behaves at the crime scene, including how they interact with the victim, may reflect their behaviour in everyday situations. For example, while some rapists might want to control and humiliate their victim, others can be apologetic. This might tell the police how the offender relates to women more generally. The significance of time and place of the crime is also a key variable and may indicate where the offender lives. Forensic awareness describes individuals who have made an attempt to ‘cover their tracks’ (i.e. hide the body/murder weapon or clean the crime scene). Their behaviour may indicate that they have been the subject of police interrogation in the past, or even that the police already have their DNA or fingerprints of file.

Question 4

What is geographical profiling?

Answer 4

• Study of spatial behaviour in relation to crime and offenders. It focused on the location of the crime as a clue to where the offender lives, works and socialises. Relevant data includes the crime scene, local crime statistics, local transport, and geographical spread of similar crimes. The assumption is that a serious offender will restrict their criminal activities to an area that they are familiar with, and the offender’s base will therefore be in the middle of the spatial pattern of their crime scenes. Earlier crimes are likely to be closer to the offender’s base than later crimes. As an offender becomes more confident, they will often travel further from their comfort zone.

Question 5

Canter and Larkin (1993)

Answer 5

• Proposed two models of offender behaviour: the marauder (who operates close to their home) and the commuter (who is likely to have travelled away from their home). Crucially, though, the spatial pattern of their crimes will still form a circle around their home. This becomes more apparent the more offences that are committed. The spatial pattern of a crime can also tell the police whether the crime was planned or opportunistic, as well as other important facts about the offender such as their mode of transport, employment status, approximate age etc.

Question 6

Strengths of Bottom-Up Approach (1)

Answer 6

+ Canter argues that bottom-up profiling is more scientific than top-down profiling because it is more grounded in evidence and psychological theory and less driven by speculation than top-down profiling.

+ Bottom-up profiling, unlike top-down profiling, can be applied to a wide variety of offences, such as burglary and theft as well as murder and rape.

Question 7

Weakness of Bottom-Up Approach (1)

Answer 7

• There have been some significant failures when using bottom-up profiling. In 1992, 21 year old Rachel Nickell was stabbed 47 times and sexually assaulted in a frenzied attack on Wimbledon Common. In 2008, following examination of forensic evidence, Robert Napper was convicted of the murder. He had been ruled out early on the initial investigation because he was several inches taller than the profile had claimed the offender would be.

Question 8

Weakness of Bottom-Up Approach (2)

Answer 8

• 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 the accurate identification of the offender.

Question 9

Weakness of Bottom-Up Approach (3)

Answer 9

• Kocsis et al (2002) found that chemistry students produced a more accurate offender profile than experienced senior detectives. This implies that the bottom-up approach is little more than common sense and guess work.