I think I read he was DD in 2012? If so he definitely got the AR556 after that, I believe they came out in 2014'sh?
What I'm finding is he had a 'bad conduct' discharge, not a DD. If that's the case, at least as I understand it, he is not automatically disqualified from gun ownership. Still trying to find confirmation on exactly what it was.
Other info is saying he was convicted of domestic violence - if that's true, that would have disqualified him.