I think this is a combination of flunkies and professional killers AQ trained. The AQ don't care if the flunkies get detained and deported and they continue to pick off Americans one at a time.
Remember the false witness? He wasn't given bail and that was for the Home Depot murder. He's a flunky for the shooter(s). For all we know, he's been identified as an enemy combatant but they're not telling us or we'd be scared, although we're already fearful.
I wondered the same thing. Could he be a prison convert/recruit like Padilla.