lesson 2 - Bottom Up Approach

Question 1

What is the bottom up approach

Answer 1

The bottom-up approach is a data-driven approach that involves using data from
crime scene and victim to build a statistical database. Statistical information is
analysed to find relationships between crimes.

Question 2

What is forensic awareness

Answer 2

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 on file

Question 3

Assumptions about investigative psychology

Answer 3

One assumption of investigative psychology is interpersonal coherence. This is
the idea that the offender behaves consistently at the crime scene and in real
life. For example, whilst some rapists want to control and humiliate their victim,
others can be apologetic. This might tell the police how the offender relates to
women more generally.
Another assumption of investigative psychology is significance of time and
place. Details of the time the crime occurred, and the place it occurred in, may
indicate where the offender is based (e.g. where they live and work) or their
mode of travel (e.g. train or car).

Question 4

Strengths of the bottom up approach

Answer 4

+ The bottom-up approach emphasises the importance of data, psychological
theory and statistical analysis which makes it more objective and scientific than
the top-down approach which is far more reliant on intuition.
+ Bottom-up profiling, unlike top-down profiling, can be applied to a wide
variety of crimes, such as burglary and theft, not just violent crimes, like
murder and rape.

Question 5

Weaknesses of the bottom up approach

Answer 5

The success of bottom-up profiling depends on accurate and detailed records
being kept on criminal databases.

• 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.
• 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 in the initial investigation because he was several inches taller
  than the profile had claimed the offender would be. Robert Napper killed more
  victims before he was finally caught

Question 6

What is geographical profiling

Answer 6

Geographical profiling is the study of spatial behaviour in relation to crime and
offenders. It focuses on the location of the crime, and evidence of the extent
of the criminal’s local knowledge, as clues to the offender’s life, job and habits.
Relevant data includes the crime scene, local crime statistics, local transport,
and geographical spread of similar crimes.

Question 7

What are the 3 key principles in geographical profiling

Answer 7

Least-Effort – A criminal will not travel further than they have to in
order to commit a crime and therefore crimes usually occur in a criminal’s
locality.
2. Distance Decay – Offenders tend to commit more crimes closer to home
than farther away.
3. Centre of Gravity Hypothesis – Where the offender is based will be the
place which simultaneously has the minimum possible distance to each of
the offence locations.

Question 8

What is crime mapping

Answer 8

Crime mapping and analysis of spatial decision making can reveal whether an
offender is a marauder (commits crime close to home) or commuter (who is
likely to have travelled a distance away from their home to commit crime
somewhere they are familiar)

Question 9

Strengths of geographical profiling

Answer 9

Lundrigan and Canter (2001) collated information from 120 murder cases
involving serial killers in the US. The location of each body disposal site was
plotted and a centre of gravity identified. The offender’s base was invariably in
the centre of the pattern. This effect was more noticeable for marauders.
+ One successful use of geographical profiling was the identification of John
Duffy known as the ‘Railway Rapist’. Duffy had committed several rapes and
murders around railway station in North London in the 1980s. Canter studied
the location of the crimes. This helped him to identify where the attacker lived
and the resulting pattern suggested the offender was a marauder.
-

Question 10

Weaknesses of geographical profiling

Answer 10

Geographical profiling is not useful for financial crimes or crimes of passion
where the offender’s behaviour is not necessarily linked to a specific location