I have a 5 unit property where there is a family that had been living there for over 5 years. They are good tenants. One of the units is occupied by my parents who do not own the property. My dad is very handy and serves as my handy man most of the time. These long term tenants are good so when a unit opened up and they asked if we can give special consideration for a relative with bad credit to move in to a recently vacant unit, we did (after background checks of course). And then a few months later, a third unit was also also rented to their relative under the same requests. The 2 relatives who moved in were not as great as them. We start issuing lease violations to them, and every time, they use each other as support and making false accusations against my parents that live on site saying they are doing illegal stuff like entering their unit while they are not there and somehow privacy issue of my parents spying/watching them in retaliation. Entering their units is totally untrue. I don’t know what to say about the privacy issue. My parents live there and have rights to look where ever they want. Plus I have video surveillance in common areas. I am really regretting renting  over half my property to the same family that is bullying my parents. I am located in Bay Area, CA. Any suggestions on how to handle this situation? They have had numerous guest violation where someone was living with them not on the lease for months at a time, plus numerous parking violations and their kids/guests doing prohibited things in common areas. Of course I only come to know of these things through my parents, so I think this is where the privacy issue stems from. But all these are actual violations of the rental agreement. Any suggestions on how to handle this situation?

Go and talk to them in person and see if you can find some common ground.  If that does not work, continue to issue lease violation notices and then non-renew at lease termination.  It's likely going to be hard to get them evicted for these items, particularly in CA and particularly during COVID.  Screening is investing.

Parking violations involve them parking in the other non related tenants spots also on way too many occasions, so I had to do something. Their guests and kids were actually causing damage to the property. Kids have broken sprinklers, cause the automatic sliding gate to go out of alignment, and damaged a lot of landscaping. Those things I also feel I cannot not enforce.  But I agree, I should probably find a lawyer.  There leases have also expired and I didn’t renew them, but that means nothing in the state of California 

@Cindy Chan   Does your lease state fines?  Keep having their cars towed if they park in spots that aren't allocated to the unit-each person gets a decal for their car or a sign to put on the dashboard.  Tell them they need to move and talk to the original family that was there and say this needs to stop.  Explain that if it doesn't, evictions will be filed for lease violations.

@Theresa Harris I don’t want to have to micro manage the parking lot like that. I would prefer to send violation warnings and move on to eviction normally. But in this cause I’m afraid these tenants are going to ban together to make false accusations against me to prevent one of them from getting evicted because they are family. Plus I don’t think it is legal for me to tell anyone to leave or move out since this is California and my area only allows evictions with a cause.

Originally posted by @Cindy Chan :

@Theresa Harris I don’t want to have to micro manage the parking lot like that. I would prefer to send violation warnings and move on to eviction normally. But in this cause I’m afraid these tenants are going to ban together to make false accusations against me to prevent one of them from getting evicted because they are family. Plus I don’t think it is legal for me to tell anyone to leave or move out since this is California and my area only allows evictions with a cause.

You'd just have to post a sign and have a towing company patrol it.