WASHINGTON — The government contractor who killed 12 people at the Navy Yard last week was driven by delusions that he was being controlled by low frequency radio waves, and he scratched the words "End the torment!" on the barrel of the gun used in the killings, the FBI said Wednesday, offering new, chilling details of the killings.
Valerie Parlave, assistant director in charge of the FBI's Washington field office, said that Aaron Alexis, 34, began the shooting knowing he would be killed. A search of Alexis' electronic devices, she said, indicates that he was "prepared to die during the attack and that he accepted death as the inevitable consequence of his actions."
Documents released Wednesday and details provided by authorities began to fill in some gaps in the time line of the Sept. 16 rampage, which ended when police fatally shot Alexis in a third-floor cubicle.
The clues about Alexis' mental state and motivations come from inscriptions found on his Remington 870 shotgun and documents found on his electronic devices.
In one document, he wrote: "An ultra-low frequency attack is what I've been subject to for the last three months, and to be perfectly honest, that is what has driven me to this."
Investigators are continuing to try to understand Alexis' "pathway to violence," Parlave told reporters. The etchings on his gun included "Not what y'all say!" and "Better off this way!"
Another scratched message, "My ELF weapon!" and other evidence gathered from Alexis' electronics indicate that the former reservist thought he was being controlled by extremely low frequency electromagnetic waves, according to the FBI.
The documents do not detail the rampage, but a haunting 30-second video provided by the FBI shows Alexis stalking the hallways and a stairwell with his shotgun in hand, and ducking behind walls when someone might see him.