NCJ Number
192773
Journal
Journal of Criminal Justice Volume: 26 Issue: 5 Dated: 1998 Pages: 425-435
Date Published
1998
Length
11 pages
Annotation
This article discusses the complex events of a crime that is the culmination of several processes emanating from the past.
Abstract
Criminal behavior is a complex sequence of events. A criminal event may occur when a motivated offender encounters a likely target without a guardian. The convergence in time and space, however, is not a spontaneous event. The sequence begins when the victim makes the decision to venture out and this coincides with the pattern of an offender who seizes the opportunity to rob the victim. Even when all possible precautions are taken, the very nature of routine activities ensures that an encounter with some offender in space and time is feasible. The system where randomness and determinism coexist suggests the characteristics of fractals that have the property of self-similarity or scale invariance. This analysis is based upon Vancouver Police Department calls for service data obtained from their Computer Aided Dispatch (CAD) system. The R/S technique, based upon chaos theory, is used in an attempt to provide a different insight into the phenomenon of temporal crime data. The higher fractal dimension for the crimes of assaults and thefts from autos indicates that their periodicity is greater than for the total calls for service. The fractal dimension provides a unit of analysis for the fluctuations of different types of calls and a different method of examining the time series data. R/S offers a method to analyze such fluctuations of specific crime series without demanding anything of their underlying nature. This analysis demonstrates that police calls for service data have a memory effect that can be identified by its fractal dimension. The technique suggests a new way to look at how the police system is functioning and raises questions about situational factors. Further examination of data for a longer period of time needs to be done before a precise value for the fractal dimension can be estimated. 3 figures, 1 table, 57 references