Roommates without Being on Lease

[Kaybreh Mathis]

Hello! We just bought an apartment building and the previous landlord was absolutely terrible. We have several tenants with roommates that are not listed on the lease. He told them the other people could live there without being on the lease because it would be more expensive for him if he had to evict them both? But he paid all utilities, so he charged them $50 extra a month and built that amount into the lease. I know this is an awful business practice. (This guy also accepted all rent in cash only so he never had to report the income.) But what recourse do I have? Thank you!