In footage released by the FBI Wednesday from surveillance tapes at the Washington Navy Yard, we receive chilling insight to how Aaron Alexis carried out his massacre.
Video and images capture the gunman entering a building in the facility, stalking the halls, sawed off shotgun in hand, looking from room to room for victims.
The FBI also released the following detailed timeline of the shooting:
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.
Watch the video below, via the FBI: