Comment by blasdel

If the call was already being recorded (say for voicemail) it can simply be subpoenaed. In the eyes of the law the defendant wiretapped themselves.

Of course the actual GPS service, involving beeping atomic clocks in space and a passive receiver in your device leaves no trail. But everybody appears to use 'GPS' to refer to "directed navigation" applications running on small computers that like to keep logs of waypoints and intended destinations. The iPhone's Maps app even takes a screenshot when you switch away from it to make it feel snappier when you return, and these pictures can be recovered forensically.