It's called Starchase. Essentially, it's a cannon that fires "bullets" that are sticky GPS devices.
CBS 12 offered an example in real life of how it's done.
Iowa state trooper Tim Sieleman seemed rather mesmerized. He told CBS 12: "If you had told me 16 years ago that I would have had a cannon on the front of my car, I wouldn't have believed it." [MORE]