Can I sue for damages and money?

You were 100% right not to sign the paper that would have allowed him to walk away from the mortgage. He made a commitment and needs to live up to it. But, now that he has moved on physically, you need to mitigate your financial damages by selling the property as soon as possible. He is half-owner and will have to agree to any sales agreement, but it sounds like he'll be happy just to be free of the obligation. So sell ASAP. Track him down with the help of a personal investigator if necessary so that you can keep him informed and serve him if a suit becomes necessary

Keep track of all expenses, and once the house is sold, sue him in civil court for his prorated share for the time he lived there. You can't expect him to pay utilities, but he should be responsible for at least a few months of mortgage payments, seeing as he skulked away in the middle of the night like a rat.

You have a right to sue to enforce compliance with the contract - so long as the contract was written in such a way as to be legally enforceable.

Real Estate law is very specific as to procedures and rules - it may cost money, but you NEED a lawyer.

Richard

I don't know about the civil law in the US, but you certainly could in the UK, and I'd be very surprised if you can't in the US, it would be very injust. You are surely equally liable for the obligations that arise from the contracts you both freely signed.

He's still liable, because his name's still on the contract.