This is probably not the case here, but IIRC there are criminal charges attached to violating NOTAMs, so there’s still some kind of deterrence.
You’d need a digital system with a gimbal, and the DJI O4 Pro alone will run you $200+. For dual lenses with different zoom levels and feed switching it’s getting pretty expensive very fast.
FPV is a skill you can learn though and for filming armed thugs I actually can't think of a better tool because it allows you to fly the drone out of LOS so you can do it from a relatively safe position while still getting footage that matters.
For extra protection you could even abandon the drone and record the video directly on your headset.
Technically true I guess, but learning to fly a recent DJI drone takes about ten minutes. You're not so much flying it, as telling it what you want and letting it fly itself. And the controller has a built-in tutorial with a simulator.