Yeah, it's one of those neighbor situations where the "problem house" is really a problem house, and then this former cop neighbor makes it worse by escalating and insulting and so on. I know from experience that if you are respectful to people, they are more likely to upgrade their poop scooping or dial down the stereo. OTOH if you make them feel like outsiders who can't ever live up to your standards, then it will escalate. People are just human, and need a way to "save face." I thought the maryjane complaint was that bullshit thing people do once they've decided they don't like somebody. Poop and noise were the real problems. (I have my own story of dog poop problems, which can be provided, if needed... or will post in Pets thread)
None of their bad neighbor shit justified being greeted at the door with a volley of bullets. The shooter was a bad cop who stopped being a cop (his one smart decision) but unfortunately still had his bad cop attitudes. And a fucking gun.