Abstract
The second study focussed specifically upon the provision of statistical offender profiling advice to investigations. A total of 312 detected murder cases from the Serious Crime Analysis Section (SCAS) database were explored to search for patterns regarding what is known about the offence at different stages of an investigation, i.e. the first hour (also known as the golden hour) within the first 24 hours and thereafter. The data were analysed to search for features which could reliably be predicted regarding the offender responsible at each of these stages. In compliance with the Pragmatic Psychology approach, the research was organic, in that the variables regarding the offence (including victim and crime scene), and the variables regarding the offender, were drawn out of the information available to the investigation and practical requirements of the SIO as articulated by the interviewees in study one. Study two was split into two parts - the first undertaking univariate and bivariate quantitative analysis (base rate frequencies; chi square; odds ratios), and the second involving multivariate statistics (configural frequency analysis; logistic regression). As the research was pragmatic, consideration was given not only to statistically significant findings, but also to potential performance if applied to future (undetected) cases. The different statistical techniques were compared to one another, and some of the more complex analyses (e.g. logistic regression) did not significantly enhance predictions from those which could be made on the basis of more simplistic methods (e.g. base rate frequency). As such, pragmatic recommendation was made as to which findings regarding the offender should be reported in different offence situations. Finally, building on previous practice advice, the thesis proposed future recommendations for SIOs, BIAS, the National Policing Improvement Agency (NPIA) and the wider police service. A programme of future research has been suggested that incorporates other aspects of behavioural investigative advice. (Abstract shortened by ProQuest.).