I am not saying that is what you are facing, but the fact they allowed unknown people to move in should be a red flag. Use a professional service.
He's an attorney specializing in Evictions/Unlawful Detainers and his office is at the northwest corner of Broadway and Long Beach Boulevard.
I'm sure he's going to tell you that once an eviction is complete with your tenant, any remaining occupants that fail to leave can be treated as trespassers and can be easily removed from the property by calling the police and having them respond.
Be certain that you handle any remaining personal property that the tenant might leave behind in accordance with the law. Very specific notices and timelines have to be given and inventory of items left must be documented very well.
Wish you the best with this,
Hope this is helpful,
Barbara Robbins-Olexa, Broker, e-Pro(R), SRES(R)
L B Brokerage
My opinion, is If the other occupants are unknown sublet occupants, you don't need to know their names, just call the police & say "there are people living in my home & I didn't authorize them to live there, go kick them out".
Before you contact the police, please speak with an eviction company, they are more familiar with the laws for legally kicking out occupants. http://www.asapevictions.com/
If you would like to stop dealing with tenants, I have home buyers for the Long Beach area, please shoot me an email directly, I don't look back on this same Trulia posting for answers after mine.
Emily S. Knell
Realtor Since 1996
Realty ONE Group