WASHINGTON — The deadly attack at the Washington Navy Yard was carried out by one of the military's own: a defense contract employee and former Navy reservist who used a valid pass to get onto the installation and started firing inside a building, killing 12 people before he was slain in a gun battle with police.
The motive for the mass shooting — the deadliest on a military installation in the U.S. since the tragedy at Fort Hood, Texas, in 2009 — was a mystery, investigators said. But a profile of the lone gunman, 34-year-old Aaron Alexis, was coming into focus. He was described as a Buddhist who had also had flares of rage, complained about the Navy and being a victim of discrimination, and had several run-ins with law enforcement, including two shootings.
The latest mass shooting quickly reignited the debate over gun control in the United States. President Barack Obama lamented "yet another mass shooting" in the U.S. and promised to make sure "whoever carried out this cowardly act is held responsible." Obama has been powerless to get gun control legislation passed by Congress amid a fierce backlash from conservative politicians and the gun owners lobby.
Monday's onslaught at a single building at the highly secure Navy Yard unfolded about 8:20 a.m. in the heart of the U.S. capital, less than four miles (6.4 kilometers) from the White House and two miles (3.2 kilometers) from the Capitol.
It put all of Washington on edge. Mayor Vincent Gray said there was no indication it was a terrorist attack, but he added that the possibility had not been ruled out.
"This is a horrific tragedy," he said.
Alexis carried three weapons: an AR-15 assault rifle, a shotgun, and a handgun that he took from a police officer at the scene, according to two federal law enforcement officials who spoke on condition of anonymity because they were not authorized to discuss the investigation.