I came across something interesting on
The Prosecutors podcast in an interview with FBI CAST expert Jay Berni
He was talking about something called "
Timing Advance" which essentially allows a cell phone company to divide up each second of coverage between multiple users to expand the number of users per tower. To do this, the tower sends a small message to your phone, and your phone sends it back. The timing of this round trip tells the tower very accurately how far away your phone is. It is so accurate, they can divide one second of coverage between multiple users by knowing how long the individual transmissions take to arrive.
As I understood it, this can happen, even if your phone is not actively doing anything with the tower (call, text, data). So for example, if your phone is not moving, it doesn't do this. Whereas if your phone is moving it may do this calculation several times in a minute.
I suspect this is how the phone company knew SMs phone was 11miles away from the Poncha tower. IIRC there are 3 connections in the final minutes, which might suggest the phone was moving. In any event, I think they can see if SMs phone distance from the tower changed significantly that night. But as we never saw the CAST report, we never saw this analysis.
BTL I believe that "11 miles west of Poncha tower" is not the most accurate number that they have, and also does not equate to PP. If PP matched the "11 miles west of Poncha tower" number in the CAST report, I think IE would have been all over that