“Investigators identified Greenwood and Crahan by using cell phone data...”
They would obviously be idiots if they brought cell phones with them (but if they did, one wonders just what kind of warrant was used to rummage through all of the data on everyone in those areas). I’m thinking that they weren’t that dumb.
My guess is that their vehicle(s) gave them away, either via license plate cameras and/or direct pings from the car to a receiver (if late model). Obviously the feds don’t want people know about this technology, so cell phone data works good here, since they’ve already disclosed it, numerous times.
I doubt any search warrant was used until after the carriers identified the numbers that were associated by time and place to the four substations by simple request.
Then the cops got warrants for full data on those specific numbers.
The carriers own all that data and have a vested interest in functioning power infrastructure.