On the Complexity and Accuracy of Geographic Profiling Strategies

Abstract

Geographic profilers have access to a repertoire of strategies for predicting a serial offender's home location. These strategies range in complexity-some involve more calculations to implement than others-and the assumption often made is that more complex strategies will outperform simpler strategies. In the present study, we tested the relationship between the complexity and accuracy of 11 strategies. Data were crime site and home locations of 16 UK residential burglars who had committed 10 or more crimes each. The results indicated that strategy complexity was not positively related to accuracy. This was also found to be the case across tasks that ranged in complexity (where complexity was determined by the number of crimes used to make a prediction). Implications for police' policies and procedures, as well as our understanding of human decisionmaking, are discussed.

Serial murderers' spatial decisions: factors that influence crime location choice

“…Geographic profiling involves predicting the home location of an at-large serial offender based on information about where that offender has committed his or her crimes (Canter & Larkin, 1993;Rossmo, 1993;Snook, Canter, & Bennell, 2002;Snook, Taylor, & Bennell, 2004;Snook, Zito, Bennell, & Taylor, 2005). In order to determine if geographic profiling will succeed or fail for a particular type of serial crime in a particular environment, it should be demonstrated that the assumptions upon which the geographic profiling technique is based correspond with what is known about the spatial decisions of serial offenders in that environment.…”

Incorporating Land Cover within Bayesian Journey-to-crime Estimation Models

“…Furthermore, centrographic methods are often presented as diagnostic routines that provide benchmarks for assessing the performance of multiple methods Paulsen, 2006a;Levine, 2009). However, single descriptive measures such as these are susceptible to outliers, and are thus often criticized for their inability to provide an efficient search strategy for locating an anchor point (Levine, 2005;Snook et al, 2005;Taylor, Bennell, & Snook, 2009). …”

“…Despite the popularity, JTC estimation models are often criticized for theoretical and empirical limitations (van Koppen & de Keijser, 1997;Rengert et al, 1999;Snook et al, 2005;Smith, Bond, & Townsley, 2009). To overcome these caveats, many researchers have pursued, with notable success, alternative heuristics for profiling offender behavior in space (Paulsen, 2006a;Snook, Canter, & Bennell, 2002;Snook et al, 2005;Taylor, Bennell & Snook, 2009). However, these techniques continue to omit the environmental factors associated with criminal opportunity and target attractiveness.…”

“…The resulting profiles will be used to estimate the location of an offender's anchor point, and will be appraised according to its efficiency in providing a search strategy. Following established evaluation methodologies (e.g., Levine, 2009;Paulsen, 2006a;Rich & Shively, 2004;Rossmo, 2005;Snook et al, 2005), the efficacy of a geographic profile will be assessed by comparing the accuracy and precision of the estimates produced by each technique.…”

“…Spatial distributions strategies based on centrographic measures are founded on the principle of least effort and often utilized in geographic profiling studies as a diagnostic routine for comparing model efficacy (e.g., Levine, 2005;Paulsen, 2006a;Snook et al, 2005). Because of its simplicity and intuitive implementation, the center of minimum distance (CMD) has become a popular measure for predicting the anchor point location relative to the distribution of crime scenes.…”