The gunman who killed 12 people at the Washington Navy Yard on Monday test-fired an AR-15 assault rifle at a Virginia gun store last week but was stopped from buying one because state law there prohibits the sale of such weapons to out-of-state buyers, according to two senior law enforcement officials. Instead, the gunman, Aaron Alexis of Texas, bought a law-enforcement-style shotgun — an 870 Remington pump — and used it on Monday as he rampaged through the navy yard, said the officials, who requested anonymity because the investigation was continuing. More proof that gun control is needed now. This attack could have been a lot worse if state lawes had been less strict. If they had been more strict it might have been prevented entirely.