Exactly right.

I cracked many inmate contraband phones.

Used the information to intercept drug drops, arrest corrupt officers, and mules.

For a burner phone to work both parties would have to have a burner phone. Cash only purchase. Kept inside a Faraday cage at all times when in a location that is attached to one of the parties involved. All phones since 1994 have GPS in them. All phones can be tracked via the cellular towers, direction and distance to within a few feet. All phones must never be in or near a motor vehicle manufactured after 2000. Especially one attached to a party involved. All phones must never be near a place you frequent.

That said, there are billions of phones to look at. You can be lost in the noise. If you are wise enough.

A single slip will give you away.

I used the cellular system like this:

Get the location of everyone in the escapee's visitation list, rap sheet accomplices, witnesses in criminal cases, phone call lists, etc...

Monitor all new phones activated in areas, bars, venues he is known to frequent.

Check every hit.

I always caught them. Most inside of 2 miles of the prison. Once 35 miles. They never got further than that.

I never missed.

Every phone call to friends and family and victims was monitored. Tracked and then the location hit. Every new phone activation inside the circle of probability was tracked. Any combination served to locate the escapees.