It's as much a caricature as a fat, floridly mustachioed police officer pounding down a doughnut in a Crown Victoria.Does the tenant have your telephone number?

I have personally called the police twice on him, but it doesn't seem to be doing anything and my landlord's response is "My lawyer and I can't do anything about him", even after sending videos of him going absolutely insane.

He was an investor first, and invested out of state while being a full-time police officer in the S.F.

If only HE (boyfriend) was on the lease and GF was not, I would believe that the landlord can call police for trespassing at this point.

I am not sure an illegal apartment constitutes the sh t hitting the fan but we have 500+ murders a year and the police typically only arrest someone in about 1/3 of them.

Did you report it to the police? 

Is it my responsibility to run there or should the tenant call the police for the noisy tenant?

Odds of the police showing up are minimal.You may have to figure some sort of bribe if you can talk to the woman next door at all. 

IF you can get a good deal, realize that in order to do anything, you're going to need a police report.  

Equipment: sheets of plywood for all downstairs openings, tools, empty boxes for their stuff, lock sets for every door, stack of 2X4's, long screws, nails, fake security cameras, no trespassing signs with California Penal Code 602 PC, gloves, masks, trash bags...If they won't leave, call the police (who won't help you but them showing up may make squatters run).