ECRI Home : Geographic Profiling : How does Geographic Profiling work? : Hit Scores

The result of a Geographic Profile is a description of an optimal search process. A search that starts in the highest (i.e. most probable) area and works outward is more likely to find the offender’s residence sooner than a random search process. Search efficiency is therefore an indicator of the performance of the Geographic Profiling model, and can be measured by determining the proportion of the total hunting area covered before the offender’s residence is encountered. This ratio is referred to as the “hit score percentage”. The smaller this number, the better the focus of the geographic profile. The actual size of the region it represents is called the search area.

The following map shows the Hit Scores of 70+ actual cases with a calculated median of 3.0% and a standard deviation of 4.4%

Definitions

Hit Score  |  The value (z-score) associated with the location of an offender’s residence or anchor point.

Hit Score Percentage  |  An indicator of search efficiency used in geographic profiling, measured by determining the proportion of the total hunting area covered before the offender’s residence is encountered. The smaller the number, the better the focus of the geographic profile.

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