A pacemaker is not a star.
I found this a few minutes ago.
https://www.digitalcitizen.life/how-far-bluetooth-range/
You misunderstand. The star example was just that. A signal has 2 components, as far as we are concerned here: the useful range where it can connect to something else, and the detectable range were the signal can be “seen,” but not connected to. Its the later the LEO were looking for.
Here’s the inside word from the guy that invented and built the detector. He was on a cable show last night. What the detector uses are high gain antennas and amplifiers - this rig can detect Bluetooth signals up to 800 feet. He also mentioned that pacemakers can send signals for 3 years.