By Tim Dees
Law enforcement agencies have always used geographic information services (GIS), but they used to be called "pin maps." One or more maps of the agency's service area had a map pin stuck where types of crimes or other incidents had taken place. Seeing the data displayed in this way made it easier to see patterns. GIS does the same thing, but provides for more and more complex types of data. Done right, it pulls the data directly from your records, eliminating the need to enter it a second time. Here's some points to consider when purchasing GIS products:
If your needs are simple, you can probably get along with an off-the-shelf software package like Microsoft MapPoint or DeLorme Street Atlas. Both will import location data from standard formats and display it on a map. Clicking on a data point shows the details of that entry. You have the electronic version of a pin map.
Sophisticated GIS tasks require sophisticated tools. ESRI is the largest corporate vendor of GIS products, and the one with the largest support network. They offer a wide variety of software and training programs to learn how to use it. GIS applications require special skills and training. There is an emerging career field for people who work solely with GIS, although many tasks can be performed by others who have GIS management as a collateral duty. In any event, you will need trained people to run your GIS program.
Open source applications
Also available are a number of "open source" GIS applications. Open source software is usually free, written by a community of users who all have access to the source code. The users constantly refine the software, posting new versions and specialized add-ins to the basic application. Open source products lack the flash of commercial packages, but often work as well or better than the high-priced types. There is an index of open source GIS products at http://opensourcegis.org.
Data creation for GIS often needs greater specificity than street addresses can provide. Large sites, such as high schools, colleges, or shopping centers may have a single address but many locations where incidents of interest may occur. It's possible to eyeball these locations on a map—assuming you're familiar with both the address and the incident itself—but a GPS recorder is a better choice. GPS recorders are like the handheld devices that hunters carry to keep from getting lost, but more precise and with the capability to link map coordinates to information of the user's choosing, such as a case number. The map points and associated information are saved in the memory of the data logger, then downloaded to a computer—hopefully, one that has your GIS software and the ability to read the data logger output.
Tim Dees is a retired police officer and the former editor of two major law enforcement websites who writes and consults on technology applications in criminal justice. He can be reached at firstname.lastname@example.org.