Years ago, some radio-geek friends & I tracked down the young punk that stole a handheld public safety radio assigned to a volunteer firefighter out of the car the punk broke into. PD & FD were both on VHF, so the radio had most PD freqs & all area FD channels.
I first did traffic analysis -- what times was he getting on the radio? It was pretty clear he was still in school, because as soon as he'd get home from school in the afternoon, he'd fire up the radio for a while, then about 20 minutes later he'd get busy with other crap for a couple hours (plus his parents were probably home), and then fire up the radio again briefly around 9PM.
At one point, he keyed up over the fire chief. It was a simplex system, so we had the fire chief come to the police station, we all listened to the Datalogger recording several times, and it was clear that the handheld radio totally covered over the chief's transmission, which was also made by a handheld. Of course we knew where the base antenna was, so we now had some clues as to the distance away from the PD/FD dispatch center (& base station antenna on the roof) that the punk was.
Since he was pretending to be a firefighter, & trying to evoke some dialog, I got permission to pretend to be "radio repair" and lured him into further transmissions, which confirmed him being in a certain area. Once I pointed out a pretty specific area, PD had a good suspect in mind. We knew the battery on the radio had to be about ready to die, so we lured him into getting on the radio by having a PD car drive down his street with lights & sirens, and sure enough, the punk must have run into his bedroom because 15 seconds later he was on the radio again. By now, the battery was so dead that it would just key up for half a second when he tried to transmit, but that half-second was long enough for me to confirm the house in question, by being up against it with no antenna on my radio, and I was able to see those half-second keyups.
The police knocked on the door, talked to the parents & got permission to search the house, & they found the Motorola handheld plus a couple thousand dollars worth of cell phones, stereos, RADAR detectors, etc. that the punk had stolen out of cars in the community.
The kid never ended up facing any federal charges for the radio violations, but was busted for larceny, recovering & concealing, etc. and unfortunately remained a bad kid, who later served some prison time as an adult, and who knows what's going on with him now...
FCC Field Office (and there was a F.O. in the region, only about 35 air-miles away) was useless because the two or three engineers were hundreds of miles away working some other case.
While some/most of us that assisted were hams, most hams in general don't have RDF equipment or experience.
Our success was mostly due to that local police department putting some blind faith into us, giving us lots of support & trust, and that it was a fairy flat, rural area without a high population density.
I assume Pasadena uses numerous voted receive sites. Anyone smart there will be looking to see which receive sites are getting the bogus signals, & at what signal strengths, in order to make an educated guess as to what the ERP of the signal is (portable vs. mobile/base radio) & if the location is static or moving, then have people go out & monitor the channel inputs in those areas, trying not to tip-off the bad guy by driving around with yagis, etc. sticking out of the car windows...
The FCC, NASA's JPL radio engineers (or the JPL ham club), & other organizations in the area would have the equipment to RDF the signal pretty easily. A couple scanner-geeks or hams cold-calling the PD & offering to assist would probably be politely refused, because the do-gooders would be deemed suspect by the PD & not get the true level of cooperation necessary from the PD's radio techs to be helpful.
I wonder if Pasadena PD has got any union problems right now, or if they've recently fired an employee? If it's someone who is just messing with Pasadena PD & not a variety of other agencies that a modified ham radio could intrude upon, then it would seem to be someone who has somehow obtained a radio just programmed with Pasadena PD channels, or it could be a field-programmable radio, but the operator just hates Pasadena PD for some reason.
I assume the local media has picked up on this situation?
Tim
SF Bay Area
