Aaron Alexis moves through the hallways of Building #197 carrying the Remington 870 shotgun.

Aaron Alexis moves through the hallways of Building #197 carrying the Remington 870 shotgun.

*Aaron Alexis was ready to die and believed he was being controlled by extremely low-frequency electromagnetic waves when he shot and killed 12 people during his attack on Washington Navy Yard earlier this month, FBI officials said at a press conference Wednesday.

The Bureau released a series of photos and a video from the Washington Navy Yard that show Alexis preparing to carry out the attack. [Watch below.]

Alexis is not believed to have been targeting any specific individuals, and apparently did not know any of his victims, Valerie Parlav, assistant director in charge of the FBI’s Washington Field Office, said at the press conference.

Alexis carved “End to the torment!” “Not what yall say!” and “Better off this way!” on the weapon he used.

Authorities also released this timeline of the attack:

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.

alexis car

Alexis drives his rental car, a blue Toyota Prius, through the Washington Navy Yard main gate.

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.

alexis backpack

Aaron Alexis’ backpack was found in the fourth-floor men’s bathroom, hanging on the back of a stall door.

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.

Alexis moves through the hallways of Building #197 carrying the Remington 870 shotgun.

Alexis moves through the hallways of Building #197 carrying the Remington 870 shotgun.

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 shot and killed Alexis on the third floor.