Bottom up approach Flashcards
Who is the pioneer of the bottom up approach?
David Canter
How is it different to the top down approach?
It doesn’t begin with fixed typologies
What features does this generate about the offender?
Likely characteristics, routine behaviour, and social background
How do they generate a profile?
They work up from evidence collected from the crime scenes to develop hypotheses about offender
What is investigative psychology?
A form of bottom up profiling that matches evidence from the crime scene with statistical analysis of typical offender behaviour patterns based on psychological theory
What is geographical profiling?
Form of bottom up profiling based on spatial consistency. Offender’s operational base and possible future offences are revealed by location of crimes.
What is interpersonal coherence?
Assumes that people are consistent in their behaviour, so there will be correlations between the crime and their everyday life
What is forensic awareness?
Offenders may be aware of investigative process, so focuses on those who have been the focus of police attention before. Behaviour may denote how mindful they are of covering their tracks.
What is smallest space analysis?
Statistical technique which explores correlations between crime scene details and offender characteristics from large numbers of similar cases
How was John Duffy caught?
David Canter analysed geographical information from similar crime scenes and details from similar attacks to draw up an accurate profile. Police re-interviewed 2000 suspects and Duffy matched Canter’s profile.
Scientific basis
More scientific, less reductionist than top down. Uses statistical techniques and computer analysis, based on psychological research. More useful in investigation and judicial process. However, relies on data gathered from caught offenders, so tells little about unsolved crimes.
Useful?
There is evidence that it is useful. Canter and Heritage (1990) did content analysis of 66 sexual assaults using smallest space analysis, identified several common characteristics, helps investigator to understand how offenders behaviour may change over time. Helpful in supporting investigation, however Copson (1995) said that only 3% of officers surveyed said that advice helped find the offender.
Danger in focusing on one profile
Ethical issues of relying too much on one profile. 1992 profile drawn up by Paul Britten to find Rachel Nickel’s killer, lots of time and money spent on one suspect, but turned out to be another suspect that was ruled out for not matching the profile. The fact that a suspect matches the profile does not prove that they are the criminal.
Geographical profiling evidence
Lundrigan and Canter (2001) collated information from 120 serial killer cases in US, smallest space analysis revealed spatial consistency. This supports Canter’s claim that spatial information can be a key factor in determining the base of an offender. However, it cannot distinguish between multiple offenders in the same area.
