The FBI has released chilling footage of Aaron Alexis, the 34-year-old Washington Navy Yard gunman, inside the building where investigators say he shot and killed 12 people and wounded four others on Sept. 16 before he was shot dead by police.
The closed-circuit video, released by the FBI on Wednesday, shows Alexis arriving at the Navy Yard in a rented Toyota Prius, entering Building 197 with a backpack and moving through the hallways with what appears to be a sawed-off shotgun. There is no audio, no footage of victims and no images of Alexis firing the weapon.
At a press conference in Washington, FBI Assistant Director Valerie Parlave announced the release of the footage along with still images and a timeline of the Alexis' activity the morning of the rampage:
7:53 a.m. - Alexis’ rental car, a blue Toyota Prius with New York plates, entered Parking Garage #28 at the Washington Navy Yard, located directly across from Building #197.
8:08 a.m. - Alexis exited Parking Garage #28 on foot carrying a backpack. Alexis entered Building #197 and proceeded to the elevator.
8:09 a.m. - Alexis exited the elevator on the fourth floor and entered the men’s bathroom carrying a backpack and a clipboard.
8:15 a.m. - Alexis crossed the hallway into the 4 West area of Building #197 with shotgun, but without the backpack or a clipboard.
8:16 a.m. - Alexis shot the first victim in the 4 West area of Building #197.
8:17 a.m. - First 911 call is received from the fourth floor of Building #197.
8:20 a.m. - Alexis left the fourth floor using the stairs and entered the third floor.
8:28 a.m. - Alexis appeared on the first floor.
8:57 a.m. - Alexis returned to the third floor.
9:25 a.m. - Law enforcement shoot and kill Alexis on the third floor.
According to the FBI, Alexis, a Navy contractor, "had legitimate access to the Navy Yard as a result of his work as a contractor and he utilized a valid pass to gain entry to Building #197."
Alexis, the FBI said, used a Remington 870 shotgun and a Beretta handgun he obtained during the course of his shooting. Both weapons were recovered at the scene.
The phrases "End to the torment!,” “Not what yall say!,” “Better off this way!” and “My ELF weapon!” were etched into the recovered shotgun, the bureau said.
"There are multiple indicators that Alexis held a delusional belief that he was being controlled or influenced by extremely low frequency ('ELF') electromagnetic waves," Parlave said. "The etching of 'My ELF weapon!' on the left side of the receiver of the Remington 870 shotgun is believed to reference these electromagnetic waves."
Parlave said a document retrieved during the investigation read, "Ultra low frequency attack is what I’ve been subject to for the last 3 months, and to be perfectly honest that is what has driven me to this."
The FBI also disclosed the gunman's activity leading up to the morning of the shooting:
Alexis was assigned to a project at the Washington Navy Yard and he arrived in the Washington, D.C., area on August 25, 2013. From August 25 to August 31, 2013, Alexis stayed at a hotel in Bethesda, Maryland. From August 31 to September 7, 2013, Alexis stayed at a hotel in the Pentagon City area of Arlington, Virginia. On September 7, Alexis moved to the Residence Inn in Southwest Washington, D.C., where he remained through September 16, 2013. Alexis began working at the Washington Navy Yard on September 9, 2013. On Saturday, September 14, 2013, Alexis purchased a Remington 870 shotgun and ammunition at a gun shop in Northern Virginia. On the same day, Alexis also purchased a hacksaw, among other items, at a home improvement store in Northern Virginia.
Alexis, the FBI concluded, acted alone.
At the White House, press secretary Jay Carney told reporters he had not seen the footage released Wednesday, “but if it is as you've described it, every American should look at that.”
“This should not be acceptable to us," Carney said at his daily briefing. "We should not be numb to that reality, and we should be doing something about it."
With Yahoo News' Olivier Knox reporting from Washington.