"A store selling firearms is required to check with NICS before making a sale. In Mr. Loughner’s case, when the 22-year-old went to the Sportsman’s Warehouse outlet in Tucson, Ariz., on Nov. 30 to purchase a Glock 19 semiautomatic handgun, a background check was performed and he came up clear, according to the store manager. That Glock was used in Saturday’s rampage in Tucson that killed six people and injured 13 others, including the critically wounded Rep. Gabrielle Giffords (D) of Arizona. Arizona, well known for its low barriers to gun possession, also prohibits the possession of firearms by anyone found to “constitute a danger to himself or others” and whose right to possess a firearm has not been restored under the requirements laid out by state law."