An internal document for the FBI reveals how the agency obtains phone location data from carriers like AT&T, Verizon, and others, and even how the agency deals with burner phones (via Motherboard).
Internal FBI Guide
Dated 2019, the document was obtained by Ryan Shapiro, executive director of nonprofit organization Property of the People, through a public records request. It was written by the FBI’s Cellular Analysis Survey Team (CAST).
CAST helps the FBI, as well as state, local, and tribal law enforcement investigations by analyzing call data and tower information. The data dumps from cellular towers can reveal approximate location data of a cell phone at certain times.
The presentation provides more recent figures on how long telecoms retain data for. AT&T holds onto data such as call records, cell site, and tower dumps for 7 years. T-Mobile holds similar information for 2 years, and Verizon holds it for 1 year.
The guide also shows that AT&T retains “cloud storage internet/web browsing” data for 1 year.