$5000 with each shell costing $500??? Sounds like they are getting ripped. A paint gun with bullets made of glue and dog tracking gps chips would be about 1/10th the price.
This is the approach Batou would take, removing the safety from his tachikoma's cannon. A less destructive method would be some kind of directional EMP weapon to knock out a vehicle's electronics. I've been reading about such developments for years—new ones keep appearing all the time—yet I never hear of a system being deployed by any police department. Perhaps they are too expensive, cause collateral damage, or have some other problem. The first microwave beam weapon of this sort that I recall seeing was on a private blog. An engineer who works with high energy systems tinkered together a microwave horn that could temporarily knock out electronics. (Most EMP devices destroy electronics, as in permanently.) The engineer posted schematics and a demo video. He mounted a camera over his directional antenna, so the viewer could see the line of fire. The video began with a running PC about 10 meters away and off to the right of the frame. At the bottom of the frame a red light came on, indicating the microwave antenna was transmitting. Then the view panned until the PC was centered and BINGO! The CRT (yes, it was that long ago) flipped out and went black, although its green power light remained on. After a few seconds, the microwave light went dark, and the PC could be seen rebooting in the background. I may have the video somewhere in my archives, but I never downloaded the schematics. A later visit to the blog showed that the schematics had been pulled. The engineer explained that a few "fans" were using the device irresponsibly.
Is there some reason the cops can't just launch a small quadcopter and have a remote pilot fly it after the vehicle?
Can they even go fast enough for that? I don't know how fast quadcopters can go, but police chases easily exceed 60 mph and I've not been under the impression that quadcopters are particularly fast, nor very maneuverable.
That requires more training to pilot the thing, rather than just firing a tracking device at the car.
True, but it's reusable. And there's no particular reason the pilot has to be on-site. One per police division would probably be good enough.
The real answer to your question is that cops already use real helicopters for that purpose. I'm cool with the GPS tracking system, though, especially if it cuts down on high-speed chases. It would save money and lives.
The advantage of a quadcopter over a helicopter (aside from fitting places a helicopter can't, like a tunnel or parking garage) is that they can be carried by any squad car for quick deployment as needed.
That's the relevant point—even if $500 a shot seems "expensive," it is still less expensive than the damages incurred in high speed chases. Of course, if the police had Reliant's command code... (And yes, such systems already exist, but work only on ultra-modern cars so equipped.)
Perhaps I should clarify----they can be deployed by any squad car. Once they're in the air, they can be piloted by someone back at headquarters. If a squad car has a voice link back to base, there's no reason they can't also have a data link.
Voice and remote control (with video) have radically different needs. And if you think we have the RF bandwidth to spare, you should take your technical breakthrough to the FCC, or at least the patent office. Or you could solve the bandwidth problem by lacing the entire city with cameras and microphoNeS (And tap cell phones, etc.) so that a fugitive couldn't possibly evade detection. Ben Franklin didn't think much of the idea, though.
Remote control costs the least by far. Streaming video does, of course, use more bandwidth than voice, but we know it's feasible (people do it every day over LTE). Whether or not the existing police radio infrastructure is sufficient is an entirely different question.