He must have been registered in another state, other than Texas. I think he was from Virginia, his parents from West Bank or Gaza.
Texas doesn't have registration by party. They just stamp you voter ID card, "Voted in the XXXX primary". Don't record anything.
All you need to know about him was that he shouted "Allah u Akbar" as he killed UNARMED soldiers and a few civilians. Soliders are still unarmed as they go about their daily business, on and off post.. at least until they get home and retrive their guns, then they are like anyone else in Texas, able to have a concealed handgun in their vehicle, with no license required.
Hasn't been any upsurge in Road Rage shootings since the law was changed to provide that. Imagine that.
Actually the county does record who votes in what primary, because voters aren't allowed to vote in more than one primary, and they aren't allowed to vote in one party's primary and another party's runoff. The political parties are allowed to have access to the lists of primary voters, and it does go into the state party voter databases.