Originally Posted by teeroux
^^ This. Its a civil property dispute. In the op's case the son doesn't have a case. The son will have a hard time explaining to the judge that he gave the guns to his mother before conviction but they have been in his father's possession and separate household for so long. Not to mention that there is the whole obvious possibility of access to the guns if they were in his mothers possession.
I disagree. I think the son certainly DOES have a case. He is not legally allowed to possess
firearms, but he is still the owner of them. A somewhat similar situation might apply to a gun owner whose wife obtains a protective order during a divorce. The shop at my range had a HUGE gun safe stored on the premises for about eight months for just this reason. The owner was under a restraining order so the police required that the guns be removed from the man's house. The cops didn't want them, so the entire safe was stored at the range until the order was dissolved. To owner wasn't allowed to possess
the firearms, but they were still his property.
In this case, the son could credibly claim that the father is preventing him (or his mother) from selling his guns. IANAL but I think this would be something akin to "theft by conversion."
I really think the OP needs to consult an attorney.