From the what I can gather, the owner doesn't have a strong enough relationship with his sister (front house tenant) to play the "family card" or appeal to the humanity in her. 

What about the State Real Estate regulatory body?

A Humane Economy by Wilhelm RopkeDon't be part of the problem.

Perhaps it takes a little bit more work than it used to, but you can still buy all-metal faucet bodies, brass cartridges, well-chromed spigots, etc at both stores.

I have done a lot of nasty, hard stuff to earn my family savings and if someone tries to steal it, it will be over my dead body.

As a "Boomer", at this stage of my life, I think it's important to take time out from business and do things that replenish my body, soul and spirit! 

And they do not see or realize it because they friggin REFUSE to use logic, intelligence and common sense.When people see some stranger calling them out and telling them "you are doing it wrong" they go on the defensive, get insulted and retaliate instead of shutting the hell up, step back see the logic in the writings and admit.. wait a sec.. this monkey is annoying BUT he has a point, and LEARN change adapt.I would have happily entertained your reservations and concerns, but I suggest learn how to approach and express politely with respect like a human being and don't get your panties all twisted up when your unwarrented snarky responses get you a fiery answer back!

I'll also treat people as humans. 

Can any body tell me their own experience investing in "multifamily apts" in Las Vegas?

off the top of my head I've seen latelyArcher (for the crass only)Californication (ahem, also for the crass)The 13th (a film, I happen to think every human on the planet ought to watch it, documents the Black American Experience)Requiem For The American Dream (commentary on American political power by Noam Chomski.