Mark Kelly, the Astronaut and Air Force Officer is entitled to purchase any weapon he wishes.
The fact is nobody would have known about it if he had not posted this on his facebook;
"I just had a background check a few days ago when I went to my local gun store to buy a .45. As I was leaving, I noticed a used AR-15. Bought that too. Even to buy an assault weapon, the background check only takes a matter of minutes. I don't have possession of it yet but I'll be turning it over to the Tucson PD when I do. "
If he had not posted that on his facebook page I would say his privacy had been violated. What he does with his legally purchased weapons is up to him. I commend him for donating it to the Tucson PD.
The guy is not only a hero, his wife was shot while serving this country.
Who made this a "news" story? Some sad little powerless and jealous person I would guess.