The ArcView Animal Movement extension for ArcView 3.x was developed by P.N. Hooge and E.R. Hooge of the United States Geological Survey for the science of ecology. It was developed to study animal migration and movement patterns, but it contains many tools for general movement study. The potential of this extension to radically advance the field of tactical crime analysis was realized in 1997. This script can be downloaded from www.absc.usgs.gov/glba/gistools.

The Spider Distance Analysis tool (under the Animal Movement menu) calculates the center point of all crimes based on x,y coordinates. Users can also animate the sequential order of the series (if the data is in chronological order), which can actually demonstrate how the subject goes from one crime to the next. This is done by creating a polyline from the point file under the Animal Movement menu.

The hypothesis is that criminals have home territories and hunting ranges. Like everyone else, they follow traffic patterns that take them to and from work, school, home, and shopping. New criminals have comfort zones they do not stray far from at first. If they continue committing crimes, their comfort zone will grow. Basically this is saying that criminals would not normally go into neighborhoods they aren't familiar with or feel they would stand out in. But if a criminal happens to be doing construction work in a new neighborhood, for instance, that neighborhood then becomes part of a new territory.

For more information, contact Kathleen Woodby, Austin Police Department (tel.: 512-974-5255, e-mail: kathleen.woodby@ci.austin.tx.us).

See also "Austin, Texas, Police Department Takes a Bite Out of Burglary With GIS."