Circle theory predicts most offenders will reside within the smallest circle that encloses a pattern of offense locations, which defines the offender's crime range. Those who reside within the crime range reflect a marauder decision pattern, with the remainder reflecting a commuter decision pattern. Random simulations of marauders were conducted to determine the failure rate of the smallest circle to correctly identify a marauder decision pattern. Failure rates were higher as the number of offenses was reduced, but were systematic and predictable. Moreover, the published rates of the marauder vs commuter patterns correspond well with the predicted failure rate. A method for estimating the true size of an offender's criminal territory is presented and it is suggested that the vast majority of offenders are likely to be adopting a marauder decision pattern, and that true commuters may be far less than indicated by the circle test.
Keywords: circle theory; commuters; geographical; marauders; profiling; statistical modelling.
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