Prospective crime mapping in operational context Final report

1. IntroductionThis report represents a summary of a project concerned with short-term burglary prediction.The work was completed in three stages, a short initial research phase to develop andestablish the accuracy of the method, a short development phase during which the systemwas refined for use in one police Basic Command Unit (BCU) with tactical implicationsidentified and discussed, and finally a six-month field trial to test whether the system could beused in an operational context and how the police engaged with it.The structure of this report largely follows the chronology of the research, thereby providingthe reader with an impression of substance and sequence. The first section is a review of theliterature that informed the project, and the second the empirical research, initial developmentand testing of the system. The third section contains a discussion of the types of tacticaloption that were originally identified as having the potential to be used with the system, or atailored variant of it, and the wider ideology of the approach. The fourth section discussesfinal refinements to the system used in the field trial, and then reviews how the system waseventually used and police officers’ perceptions of its utility. Lessons learned regardingimplementation are also highlighted and discussed. In the penultimate section, changes inpatterns of crime coincident with the work are explored, and in the final section futuredirections and recommendations are discussed.Background and past researchCriminological research has demonstrated that crime is concentrated. For all crime typesanalysed, a small number of victims are repeatedly victimised and hence experience a largeproportion of crime (for reviews, see Pease, 1998; Farrell, 2005); a large proportion of crimeoccurs in a small number of areas; and a small number of offenders commit a large proportionof crime (e.g. Spelman, 1994). In relation to the geographical distribution of crime, thismanifests itself as spatial clustering, with ‘hotspots’ of crime such as burglary being a typicalcharacteristic of deprived areas (e.g. Johnson et al., 1997). These findings conform to what ismore generally known as the 80:20 rule. This pattern is not confined to crime but is a moregeneral phenomenon. For instance, a small proportion of the earth’s surface holds themajority of life on the planet, and a small proportion of earthquakes account for the majority ofdamage caused by them (Clarke and Eck, 2003).For burglary, the focus of the current research, the relationship between different types ofconcentration has also been studied. Specifically, are incidents of repeat burglaryvictimisation the work of a common offender, or do different offenders simply exploit the sameopportunities for crime? These explanations have been referred to within the literature as theboost and flag hypotheses, respectively (Pease, 1998). A number of approaches toinvestigating these hypotheses exist, but perhaps the most direct is to examine data fordetected offences. In their analysis of a sample of data for offenders detected for burglaryoffences, Everson and Pease (2001) demonstrate that 86 per cent of the incidents of repeatvictimisation were committed by the same offenders (see also Everson, 2003). Furthercorroborative evidence comes from studies in which offenders have been interviewedregarding their offending behaviour. Typical findings illustrate that around one in threeburglars admit to returning to the same property to commit a further offence (Gill andMathews, 1994; Ashton et al. 1998) and their reasons for so doing include the following:“the house was associated with low risk …., they were familiar with the features of thehouse …., to get things left behind or replaced goods.”Ericsson, 1995Perhaps the most succinct account was given by a Scottish burglar to Mandy Shaw. Uponasked why he returned, he replied “Big house, small van”. Thus, whilst recognising that somerepeat offences may be committed by unrelated offenders, a consensus of opinion isemerging that repeat victimisation is largely the work of the same offenders. A further findingthat supports this conclusion and which has immediate crime prevention implications is the1