Can my boyfriend beat the case if he was arrested for a gun that was stolen and was found under the passenger seat of my car?

My boyfriend was arrested for a gun that was found in my car. Underneath the passenger side where he was sitting, the gun, I believe was involved in a home invasion and not quite sure if they're trying to say that it was stolen from the home invasion or used during Invasion. I'm not sure but I know that he was arrested for the gun. Can he win the case, if so, what would be his defense?