The value of collecting evidence from GPS devices has been well established over the last several years. GPS evidence has played a major role in several high profile cases ranging from terrorism to homicide to kidnapping. Most of the time as investigators, we tend to focus on collecting evidence as part of criminal investigations, however GPS evidence can play a significant role in many other types of investigations such as accident reconstruction and search and rescue cases.

Most investigators think in terms of being able to obtain GPS evidence in the form of the “breadcrumb trail” known as trackpoints, but much more data is available from these devices. This article will provide some basic information on the types of evidence and devices an investigator may come across.

Standard GPS Data
There are four main types of data that are constantly available across almost all GPS devices. These data types can be divided into two categories: system level information and user inputted data.

System Level

- Trackpoint: A trackpoint is a location stored by the unit as a record of where the GPS has been. When the GPS unit is turned on, and has acquired satellites, it will begin to record an "electronic breadcrumb trail." The trackpoints are created automatically by the unit and cannot be changed by the user. The unit, by default, automatically decides how often to create trackpoints. The user may also specify to create track points based on a specific time or distance interval.

- Track Log: The track log is the complete list of trackpoints that the unit has created. This track log is created such that if a user wants to retrace his or her steps, it is possible to perform a TrackBack. The unit will then navigate the user from point to point in the track log to take the user back to his or her starting location.