So he was a straw purchaser?
you bad! you bad! you bad! gimme hi 5 bro!
Maybe he bought it from a police-supply store so he could avoid the 15% excise tax on the firearms. He should have a letter from his police chief stating it is intended for duty purposes, which gets filed along with his 4473.
Or maybe he just showed his astronaut badge, and that was good enough for them. Or maybe he got an over-the-phone waiver from DOJ.
Hell, buy a couple plastic "blue guns", and you won't scare the crap out of people by sweeping them with a real weapon. Still a no-class move by our self-proclaimed "firearms safety advocates", but that just makes you a jerk, rather than a threat.
Straw purchaser for the Tucson PD?