The way I see it...
Its time to tkae out the trash!
Cops wouldn't care if there was one less gang banger on the streets. You were openly carrying anf he still approached. He probably thought you didn't have the nads to use it. Hell, it could have been that
guy that was breaking and entering. I don't go looking for trouble but if it finds me and pursues me for 2 blocks, I won't wait for him to put a round in my back. I will turn around and ask him exactly what the f he wants and if it is a bullet between the eyes. I respect human life but scum of the earth is scum of the earth.
Best advice I can give, carry non-lethal defenses as well such as a powerful pepper spray. I've heard Fox Labs stuff is good stuff but I haven't tried it personally. I'd spray him in a heartbeat since it isn't lethal force. Keep it on your non-gun side and have easy access to it. I also suggest you carry a decent flashlight such as a Surefire. Their G2 Nitrolon is a great deal since you get the same output as the 6P. You can also switch it for the high output lamp for about $25. At least you will be able to see him clearly and exactly what he is doing. You might look like a commando with a gun, pepper spray, and tactical light, but then again, that would be a great deterrent!