GPS data files and the visual representation of the GPS location data on maps can, in many cases, only provide analysis from a single viewpoint. Where was the vehicle or Smartphone at a specific date and time, and what was its activity before and after that date and time?

Other location-based data and evidence may be available, which can be used to cross-reference the GPS location data, providing more detailed information to answer specific questions.

Additional location information may come from many sources, such as:

• • • Witness statements. Cross-reference any date/time and location statement with GPS data. Do they match?

• • • CCTV footage is available from many sources and may capture a vehicle at a specific location. Again, the location of the CCTV camera and the field of view can be cross-referenced to the GPS data. In one case, evidence of CCTV images of a car of the same make and model was used to state that the vehicle travelled a particular route at a specific time. The vehicle registration was not explicit in the image. GPS data proved that the vehicle was approximately 6 miles from that location.

• • • Cell Site / Call Data Records. If these are available, generally only in criminal cases, the communication Service Providers often capture cell site locations used by a mobile phone. Each Cell Site has an address associated with its physical location and coverage area, which can be again cross-referenced with the GPS data.

• • • Google Timeline. Although not as robust as GPS data from a vehicle telematics or tracking system, Google Timeline location data is a good source of additional information for analysis if it is available.  
    • Smartphone Activity Trackers and Health Apps. Many different health and activity apps are available for smartphones. Many of these Apps record location information taken from the phone’s GPS. This data can be exported and used as a good source for location cross-referencing.

Several other location data sources are available and can assist in the analysis, and the availability of such data should be explored.

Matching the GPS data with additional location data and information expands the analysis. It gives a fuller picture to answer questions and confirm or disagree with any location and date/time references in witness statements.