[dad911]

He's not a squatter, for all you know he may have a verbal, lifetime lease for free.

As P-O-P said, I'd seek legal advice, and at least get something about the terms of his living there from the current owners, in writing, so you have something to fall back on. It's going to be your word against his, and last time i went to court for eviction in NJ, the tenant is always right, and gets a free public defender.

Since there is no 'security deposit' for the tenant, I'd also want to escrow $$$ from closing for eviction costs, lost rental income, and damage he may cause leaving.

You are inheriting their headache, make sure it's worth it in the worst case.