The newly emerging area of Investigative Psychology provides a behavioural science basis for crime detection by examining investigative processes and criminal behaviour. It draws upon a range of material collected by law enforcement agencies that is not widely utilised in the social sciences. This may be regarded as a form of non-reactive, unobtrusive data that has many of the advantages originally promoted by Webb, Campbell, Schwartz and Sechrest (1966) and more recently explored by Lee (2000). The value of such data, derived from police sources, has been demonstrated in a variety of Investigative Psychology studies. However, law enforcement material is not usually collected as data but rather as evidence. Consideration is therefore given to how to address the challenges this poses. The unobtrusive measures derived from police investigations provide a different perspective on crime and other aspects of human actions from that based on more conventional sources of data such as questionnaires and interviews. To assist in the effective use of measures derived from police information a framework for considering this material is proposed reflecting the range of sources of measures that Lee (2000) identified; personal records, running records, physical traces, and simple observation. As in other areas, close attention to the methods of collecting such material can considerably improve its utility. The measures being utilized in Investigative Psychology therefore offer some fruitful directions for other areas of social science research. Development of these measures can also improve the effectiveness of criminal investigations. Key words: Offender Profiling, Investigative Psychology, and Archives
Investigative Psychology and Unobtrusive Measures
As described by Canter and Youngs (2003), the newly emerging field of Investigative Psychology grew out of the need to provide a scientific basis to replace the anecdotal activity of 'offender profilers'. It sets out to provide an understanding of the processes of collection of investigative information and how that can be most effective, the development of models for making appropriate inferences from that information, and the contribution to and study of police decision-making. The central questions of this field are therefore about the salient aspects of criminal activities, the basis for linking a series of crimes to a common offender, and procedures for guiding the prioritisation of suspects (Canter & Alison, 1999a).
Although the research questions central to Investigative Psychology share concepts and methodologies with other areas of psychology, most notably the study of individual differences (Canter, 2000a), they form a distinct subset of issues that differ from those focal to the more general area of Forensic Psychology (cf. Wrightsman 2001). Forensic Psychology tends to focus on the treatment and management of offenders once they are caught. Investigative Psychology focuses on how behavioural science can help in the detection of offenders or the investigative issues that could aid the defence or prosecution of suspects.
In order to develop their research methods Investigative Psychologists have found it fruitful to draw on a wide variety of sources of information. This is most often the information available to law enforcement agencies collected for the purpose of police investigations. To make effective use of the information it has to be captured, found, or retrieved in ways that are directly analogous to the broader development of 'unobtrusive' and 'non-reactive' measures that Lee (2000) describes.
This material is typically 'unobtrusive' in the sense proposed by Webb, Campbell, Schwartz, and Sechrest (1966) to refer to "data gathered by means that do not involve direct elicitation of information from research subjects" (Lee, 2000, p. 1). They are also in many cases non-reactive because the absence of the person carrying out the study at the time the information is generated removes the possibility of any direct influence from that researcher (Webb, Campbell, Schwartz, Sechrest, & Grove, 1981). …