The FBI released a series of photos as well as video footage Wednesday of alleged Washington Navy Yard shooter Aaron Alexis as he navigated through Building 197 carrying a firearm.
In the video, the 34-year-old former Navy reservist and IT contractor is seen wielding a shotgun as he roams down hallways and stairwells in search of victims. Alexis is shown wearing a dark blue-and-white shirt and dark trousers. On Sept. 16, he allegedly killed 12 people inside the Navy Yard building before he was subsequently killed in a shootout with police.
At a press conference Wednesday, FBI officials announced Alexis was prepared to die and held onto the delusional belief that he was being controlled by extremely low-frequency electromagnetic waves, or ELF waves, reports the Huffington Post.
On the gun he used during the rampage, it was discovered that Alexis carved the words "End to the torment!" "Not what yall say!" and "Better off this way!"
There was no indication that Alexis targeted any specific individuals during the shooting spree, nor did he know any of his victims, said Valerie Parlav, the assistant director in charge of the FBI's Washington Field Office, at the conference.
She added that Alexis had a well-documented history of mental health issues.
"There are indicators that Alexis was prepared to die during the attack and that he accepted death as the inevitable consequence of his actions," she said, according to the LA Times.
Alexis grew up in Brooklyn with his parents and lived in Texas, New York and Washington State in recent years. He spent nearly four years in the Navy as a full-time reservist from May 2007 until January 2011 before he received a general discharge for "misconduct" due to two events involving a firearm.
Watch video footage from the shooting spree below: