I could be wrong but it sounded like OP said that the one mobile is empty now (tenant moved) and that the problem tenant is hanging out at the empty unit. If that is true, then he can keep trespassers out.
correct the property next to him is empty, has been for nearly 2 months and i go out every day working on it getting it ready to sell. the probation and her supervisor came by today :)appreciate all the comments and trying to help me with info. i hope i never do this again in my lifetime LOL good luck to all.