UPDATE: The FBI is denies suggestions that Aaron Alexis used an AR-15 semi-automatic rifle.

In the wake of the tragic Washington D.C. Navy Yard shooting yesterday, one question sure to be on most people’s mind is: who is Aaron Alexis, the gunman who killed 13 innocents? Reports are beginning to surface that shed light on the former Texas resident and New York native ranging from his religion to his having been treated for mental health issues.

But, eerily, a motive behind the shooting has yet to be uncovered.

The 34-year old was once a member of the Navy Reserves stationed in Fort Worth, Texas where he spent four years only to be generally discharged. According to CBS, his military records indicate “a pattern of misconduct.”

He then took up work as an independent defense contractor, working at times at the same Navy Yard he unloaded an AR-15 semiautomatic rifle, shotgun, and handgun.

CBS continues to note that it was his work with the Reserves, where he served as an aviation electrician’s mate 3rd class, and his subcontracting work at the Navy Yard that he was granted access to the secure facility, for he “maintained a secret clearance from his work with the Navy.”

That kind of access coupled with a history of mental health and a chip on his shoulder all played a crucial role in yesterday’s catastrophe. Even scarier, though, is his established history with gun violence.

The Associated Press is stating that Alexis “had been treated since August by the Veterans Administration for his mental problems,” which are reported to include paranoia and insomnia, though the Navy failed to declare him mentally unfit for service which would have reneged his security clearance.

His discharge from service left him on difficult times financially and he struggled to pay his bills after “the benefits he believed had been withheld” failed cover his growing debts, says the Los Angeles Times. This led to a boiling discontent with the sea-faring branch of the American armed forces. Consequently, he “drank alcohol, always carried a gun and ‘acted childish — not like a 34-year-old.'”

The gun he always carried led him, in part, to more trouble as he  had already been “arrested after firing a bullet through his downstairs neighbor’s ceiling and then asked to leave his Fort Worth apartment,” per the Washington Post.

And that’s not the only gun-related incident Alexis was involved in.

He was arrested in Seattle back in 2004 for, according to The Seattle Times, “shooting out the tires of a construction worker’s car in what Alexis later described as an anger-fueled ‘blackout,’ police said. Alexis attributed his action to trauma he witnessed after the Sept. 11 terrorist attacks, according to Seattle police.”

Whether it be from frustration, decomposing mental health, or his bloodthirsty commitment to revenge, something clicked in Alexis’s time-bomb of a mind that resulted in the untimely ending of 13 blameless lives.

Authorities believe Alexis is the sole shooter in the incident despite various reports that suggest as many as three pulled their triggers. Should it be proven that more were involved, we’ll be sure to update you accordingly.