Newly obtained emails from the man who went on a shooting rampage inside the Washington, D.C. Navy Yard could reveal the motive behind the deadly shooting.
According to the New York Post, Aaron Alexis took to an online outreach group just two weeks before the September 16 shooting that left 12 people dead and several injured.
Alexis reportedly believed that the Navy was targeting his brain with low frequency waves he called "the Elf weapon," a phrase he also carved into one of his weapons.
In one of his emails, he said, "I have not allowed them to scare me off my job, but I fear the constant bombardment from the ELF weapon is starting to take its toll on my body."
He claimed he started experiencing this after an incident at Norfolk International Airport.
Alexis, a government contractor from Ft. Worth, Texas, started an assignment at the Navy Yard just a week before the shooting and didn't appear to be motivated by any kind of workplace dispute, officials said.
Last month, FBI released chilling surveillance video that showed Alexis pulling into the Navy Yard parking garage in a rented blue Toyota Prius before moving through Building 197. Scrawled onto the shotgun he carried were several phrases, including, "End to the torment," "My ELF weapon," and "Better off this way," authorities said.