Law enforcement may locate a cell phone in a number of different ways:
- Using GPS technology that triangulates approximate coordinates for the cell phone handset. This technology may be found in other devices too, including devoted GPS trackers, wearable health and fitness trackers, smart watches, and some laptop computers. Because it’s calculated by a GPS receiver within the device itself, this information is not necessarily in the possession of a mobile carrier, and it may need to be obtained directly from the device. (But mobile apps may have passed GPS data to an app developer, and law enforcement may then request the location information from the developer.)
- Obtaining location information from the cellular network provider via “pinging” or triangulation. When a modern cell phone is pinged, it determines its latitude and longitude via GPS and sends these coordinates back via the SMS system (the same system used to send text messages). This means that in instances where a fugitive or other missing person has a modern cell phone (and that the phone has power when being pinged) that the cell phone can be located within a reasonable geographic area - some say within several feet of the cell phone. All cell phones sold in North America since late 2003 have this capability due to the requirements of the enhanced 911 standard requiring location information in the event of an emergency.
- With the older style analog cellular phones and digital mobile phones that are not GPS capable, the cellular network provider can determine where the phone is to within a hundred feet or so using “triangulation” because at any one time, the phone is usually able to communicate with multiple cell towers. The cell towers are typically a few miles miles apart (less in urban cities) and a phone is usually within range of at least three of them. By comparing the signal strength and time lag for the phone’s carrier signal to reach each tower, the network provider can triangulate the phone’s approximate position.
Where Cell Site Location Information Is Used
Cell site location information is tracked relatively everywhere in the United States, and regularly requested by police officers, sheriffs, detectives, intelligence agents and any variety of law enforcement employees.
What the Technology Looks Like When It Is Used
Criminal defense attorneys who fear that their clients may have been subject to having their cell site location information obtained by law enforcement should look for the following:
- Seizure of your client’s cell phone or other digital device with location tracking capabilities such as personal health trackers like Fitbits and Apple watches.
- Any mention of cell phone extraction software, like Cellebrite, Pen-Trace, Secureview, Oxygen, FTK Imager, Encase, MSAB XRY, or E-fense Helix3.
- Any subpoenas or search warrants addressed to cell phone service providers like AT&T, T-Mobile, Verizon, Sprint, Boost Mobile, MetroPCS, etc.
- Any discovery referring to cell tower location information, GPS data, or cell phone extraction reports that include location information
- Any subpoenas or search warrants looking for “accounts associated with the area near” a specified location
This is a short list of some of the likely indicators that your client's location information may have been compromised and shared with law enforcement, but it is not an exhaustive list of all possible indicators.