Editing Aaron Alexis (section)

==Prior to shooting==
Aaron Alexis, the perpetrator, arrived in the Washington, D.C., area on or around August 25, 2013, and stayed at various hotels. At the time of the massacre, he had been staying at a Residence Inn hotel in southwest Washington since September 7. He was working for a subcontractor on a Hewlett-Packard Enterprise Services contract and staying with five other civilian contractors.

On Saturday, September 14, two days before the massacre, Alexis visited the Sharpshooters Small Arms Range in Lorton, Virginia, 15 miles (24 km) south of Washington. He tested out an AR-15 semi-automatic rifle but did not seek to buy it, a lawyer for the store said.

Initial reports indicated that one may have been used in the Washington Navy Yard shootings. Instead, after purchasing ammunition and test-firing the AR-15, Alexis inquired about buying a handgun at the range, according to an attorney for the store However, since federal law does not allow dealers to sell directly to out-of-state residents, and the gun would have been shipped to a licensed dealer in his home state, Alexis then selected a Remington 870 Express 12-gauge shotgun, since rifles and shotgun may be directly sold to out-of-state residents, and bought it along with two boxes of shells containing about 24 rounds, after passing a state and federal background check.