I have been battling a persistent roach problem in my apartment in Arizona. I posted a question earlier this week regarding the situation. My landlord is refusing to let me out of my lease with out paying the penalites even though the apartment is not habitable and they are in breach of the warrant of habitability. Someone suggested getting a copy of my lease to review. I did so and noticed that the lease is not signed by the owner/agent even though there is a space for them to sign. It says at the top that it is a legally binding contract. Is the contract valid if it is not signed by both parties?

They probably have another copy of the lease signed by you. They can sign it any time they want.