bottom up approach

Question 1

bottom up approach

Answer 1

profilers work up from evidence collected at crime scene to develop hypotheses about likely characteristics and social background of offender.

profile is data driven and emerges as investigator engages in more deeper scrutiny of details of offence

more grounded in psychological theory than top down

Question 2

investigative psychology

Answer 2

applies statistical procedures with psychological theory to analyse crime scenes

aims to establish patterns of behaviour likely to occur across crime scenes to develop statistical database which acts as baseline for comparison - used to determine whether series of offences are linked and likely to be committed by same person

interpersonal coherence - way offender behaves at scene and interacts with victim may reflect their behaviour in everyday situations

Question 3

geographical profiling

Answer 3

based on principle of spatial consistency and idea that offender’s operational base and possible future offences are revealed by geographical location of previous crimes.

assumes serial offenders restrict offences to geographical areas they’re familiar with so understanding spatial pattern of behaviours provides investigators with ‘centre of gravity’ - likely to include offender’s base

canter’s circle theory proposed 2 models of offender behaviour: marauder - operates in close proximity to home base and commuter - likely to have travelled distance away from their usual residence.

Question 4

evaluation - evidence supports geographical profiling

Answer 4

Lundrigan and Canter - collated info from 120 murder cases involving serial killers in USA.

used smallest space analysis and found spatial consistency in behaviour of killers. location of each body disposal site was in different direction from previous sites, creating ‘centre of gravity,’ offender’s base was always located in centre of the pattern. effect was more noticeable in marauders

supports canter’s claim that spatial information is key factor in determining base of offender.

Question 5

evaluation - scientific basis

Answer 5

canter argued bottom up profiling is more objective and scientific than top down approach - more grounded in evidence and psychological theory and less driven by speculation and hunches.

With aid of advanced AI, investigators are able to manipulate geographical, biographical and psychological data quickly to produce insights to assist investigations. Similarly, field of investigative psychology has recently expanded to include areas such as suspect interviewing and examination of material presented in court, which supports its utility in all aspects of the judicial process.

Question 6

evaluation - mixed results

Answer 6

despite having many successes, there’s also been some significant failures of bottom up approach.

copson surveyed 48 police forces and found that advice provided by profiler was judged to be ‘useful’ in 83% of cases, but only led to an accurate identification of offender in 3% of cases.

Kocsis et al found chemistry students produced more accurate offender profile on a solved murder case than experienced senior detectives.