In the absence of forensic evidence (such as DNA or fingerprints), offender behavior can be used to identify crimes that have been committed by the same person (referred to as behavioral case linkage). The current study presents the first empirical test of whether it is possible to link different types of crime using simple aspects of offender behavior. The discrimination accuracy of the kilometer-distance between offense locations (the intercrime distance) and the number of days between offenses (temporal proximity) was examined across a range of crimes, including violent, sexual and property-related offenses. Both the intercrime distance and temporal proximity were able to achieve statistically significant levels of discrimination accuracy that were comparable across and within crime types and categories. The theoretical and practical implications of these findings are discussed and recommendations made for future research.
Keywords
ProximityOne of the most compelling and well-supported findings in criminology is that the majority of crime is committed by a minority of offenders (e.g. Kershaw, Nicholas, & Walker, 2008;Laub, 2004;Piquero, Farrington, & Blumstein, 2007). In the United States (US), for example, estimates suggest that approximately 5% of offenders are responsible for 30% of felony convictions (Office of the Legislative Auditor, 2001). Findings such as these suggest that an effective way for the police to tackle and reduce crime is to target serial and repeat offenders who are responsible for a disproportionate amount of crime.Targeting serial offenders specifically, however, requires the police to identify serial offenses (referred to hereafter as linked crime series), which are essentially two or more crimes committed by the same offender or the same group of offenders (Woodhams, Hollin, & Bull, 2007). The most reliable way of identifying linked crime series is through the recovery of forensic evidence, such as DNA or fingerprints, left at the scenes of several different crimes (Grubin, Kelly, & Brunsdon, 2001). However, despite the impression that television programs such as CSI create, the availability of forensic evidence is surprisingly limited, with less than 1% of recorded crimes yielding such evidence (House of Commons, 2005). Therefore, the police often need to rely on other approaches to linking crime. One potential alternative is to use behavioral similarity, whereby crimes that show evidence of similar offender behavior are judged to have been committed by the same offender/s (referred to as linked crimes), whereas those that involve different behavior are said to have been committed by different offenders Running head: Linking Different Types of Crime 3 (referred to as unlinked crimes). This procedure is known by several names, including linkage analysis and comparative case analysis, but the term behavioral case linkage will be used in the current paper.
Behavioral Case LinkageBehavioral case linkage is an investigative procedure that has received growing attention both prac...