Back in the day, I found that calling the police and using the code "5150" completely bypassed the problem of long arrival times (which could be up to two hours from the time one actually called 911) in my densely urbanized "community."
For example, I came home from work one day to find some ex-convict bums camping on my front stoop... literally. I confronted them and they told me to "hit the road." Well, that's my place so I simply let myself in through the back and considered arming myself and removing them using violent force... something I had done before with a rather large (and prone to violence) transplant from Chicago 1/2 Sicilian 1/2 Irish friend of mine on another occasion when a tribe of tweakers (e.g. feral meth IV users) had begun squatting at his relative's house in the high desert.
Honestly, that was fun. They scattered like roaches jumping through windows and running for their lives after a rather brief stand in which we pummeled the ring leaders pretty good before letting a couple of warning shots ring out. The only one that remained was a big old grizzled ex-con biker in a corner of a room that wasn't afraid of nothing. So, we treated him with respect and told him we were reclaiming the property for family and he would have to leave but that because he conducted himself as a man and followed the code we'd help him out. We gave him some money, filled up his pack with food from the cupboards and whatnot and drove him to where he needed to go. Saw him later too and we were always cool with that one.
Anyways, I had things to do and didn't really want to bounce them solo at that moment as it turns into an ugly legal case if you actually end up shooting one of them so instead I tried something new. I picked up the phone and told the 911 operator I had a "5150" in front of my place and, even though I was neighborhood watch, I couldn't guarantee the safety of the residents of the neighborhood.
Holy cow! They came in from all directions within ten minutes! At one point, three police officers had one of the ex-convict bums lifted in the air off his feet and were stuffing him headfirst in the back of a squad car. Lol.
Oh well, they made their choices in life... same as me... same as all of you. Just say no to drugs and alcohol kids.