The Federal Bureau of Investigation announced on Wednesday that Aaron Alexis, the gunman who killed 12 people in a shooting rampage at the Washington Navy Yard, believed that he was "being controlled or influenced by electro-magnetic waves" at the time of the shooting, according to CNN.
Valerie Parlave, assistant director in charge of the FBI Washington Field Office, said that they believe that Alexis acted independently in the shooting rampage. The FBI also believes that Alexis was not attempting to target any specific target, according to the BBC.
"We have found relevant communications on his electronic media which referenced the delusional belief that he was being controlled or influenced by extremely low-frequency electro-magnetic wave for the past three months," Parlave said.
The FBI also released images of the Remington 870 shotgun with a sawed-off barrel and stock Alexis used in the rampage. Alexis carved messages into the side of the gun. The messages say "Better off this way," "End to the torment," and "Not what y'all say," according to the New York Daily News.
The FBI investigation was also able to determine that Alexis believed that he was not going to survive the ordeal by inspecting electronic media that they found in his belongings, according to CNN.
"[Alexis] was prepared to die during the attack and that he accepted death as the inevitable consequence of his actions," Parlave said.
Alexis was able to gain access to the Washington Navy Yard because he had a secret-level security clearance despite having a history of gun related charges and a history of mental illness, leading to questions about how Alexis was able to pass a background check.
An investigation by Reuters has found that at least 350 faulty background checks have allowed people to receive security clearances they should have been denied in the years between 2004 and 2012.
