There's networks of these things, so you can't trust what is said. The host agency may keep for 30 days, but exchange data with third parties, through organizat

There's networks of these things, so you can't trust what is said. The host agency may keep for 30 days, but exchange data with third parties, through organizations like NLETS, private collaborations and informal exchange. I'd assume with NLETS searches that the Feds have an overwatch capability and spy on the spies so to speak. This stuff started with "drug corridors". Police and Feds can and do track vehicles on the I-95 corridor from Maine (and Plattsburgh to NYC) down to Miami as early as 12 years ago. NYT covered it a few years back -- basically they get multiple LPR hits and are usually able to do facial recognition on front seat passengers. If you driving Florida->NYC and stop for a cheesesteak in Philly, you may get some attention up the road. There's also a growing network of commercial LPR services. Most tow trucks, many parking garages and some delivery vehicles scan and correlate license plates -- repo guys can find wanted cars in hours these days. Also, most traffic cams are saving 24x7 video with LPR.