Never if you're in the US. You call the cops and now you have two problems instead of one and the new problem is guaranteed to be trigger happy.

If it can't be helped. Like, I wish a lot of shit was settled without law enforcement because things become more complicated once they get involved. And sometimes a lot of money just to get the justice system to do shit. With the off-chance that nothing will be done at all.

I've only ever had to call the cops on two occasions and that's to deal with a noisy tenant, simply because my apartment management are a bunch of lazy assholes who simply refuse to evict people who have broken lease agreements multiple times.

My record with cop encounters has been fairly positive to date, too and I'd rather keep it that way.

If you're ok with the possibility of someone (potentially you) dying, call the cops

I called recently when somebody was trying to break into my car while I was in it. Not that it made any difference. I managed to get away and never heard back from the cops.

I should get a concealed carry permit.

German here, with relatively moderate bullpigs. I never had bad experiences with them, and most reports of right-wing content (eg. in chats) pile in eastern germany (saxony etc.). And abuse from them is pretty rare afaik, but there are famous reports of drunk people being killed and one drunk non-white person being burned (maybe alive), again in eastern germany. Overall, here in western parts, I would trust them. Basically with everything. In eastern germany I'd be very careful with anything a right-winger might be biased against.