In his first public remarks on Monday's shooting spree at Washington Navy Yard that left 13 people dead, including the gunman, FBI Director James Comey told reporters today that the rampage was carried out indiscriminately. Aaron Alexis, the former Navy reservist who carried out the massacre, was "wandering the halls and hunting people to shoot," Comey told reporters, according to the New York Times.
Comey confirmed some previous eyewitness accounts, and clarified others. Alexis, who was working for an information technology firm with a Navy subcontract, arrived at the yard's Building 197 about 8 AM on Monday, and headed for the fourth floor. He carried a bag into a bathroom, and after a few moments, emerged into the corridor wielding a sawed-off shotgun and started shooting at anyone he encountered, Comey said.
In total, 12 people along with Alexis, who was killed by a Metropolitan Police Department officer, died in the rampage. Comey said Alexis shot at people on the building's fourth floor, third floor, and lobby, where he killed a security guard. The shotgun, a Remington 870 purchased last weekend at a gun shop in Lorton, Virginia, was partially sawed down on the butt and barrel. Alexis also purchased 24 shotgun rounds, and Comey said he picked up the security guard's handgun after exhausting his shotgun ammunition.
Comey's statements fill in much of the timeline of what transpired on one of the bloodiest days in Washington's history, but still unknown is just how Alexis came to carry out such a horrific act is still unknown. Law enforcement authorities in multiple locations say he suffered from paranoia and anger issues, but he was never declared unfit to work for the Navy.
Also still in question is what happened with a US Capitol Police tactical unit that attempted to respond to the Navy Yard shootings in the early minutes of the carnage, but was turned back by a supervisor.
UPDATE, 9/20/13: While Comey said the shootings appeared to be at random, additional law enforcement sources say the spree might have started over a dispute between Alexis and his coworkers, the Washington Post reports. “Our belief is that the people who were shot first were people he had issues with where he worked, people he had some sort of a dispute with," a law enforcement official told the Post. After that, Alexis started firing at anyone he came across, the official said.