The FBI identified the deceased gunman in today’s Washington Navy Yard shooting as Aaron Alexis.  The agency released photos of him and is asking for the public’s assistance in providing any information concerning Alexis.

The reporting on today’s incident is still very fluid – in fact, much of it kept changing as I was in the midst of writing this post and will likely continue to change.  That said, we’ll try to offer some of the basic background here and will update with new developments as more details are confirmed.

Twelve people were killed in today’s incident, plus the gunman.  Initial reports indicated that there may have been more than one shooter (though it’s unclear if this is still the case), and the gunman was initially misidentified.  Officials initially said they believed Alexis may have used the ID of a former employee in order to gain access to the facility.

Alexis is said to have recently resided in Texas, and was originally from New York.  He spent four years as a Navy reservist before being discharged and then worked for a subcontractor to Hewlett Packard.

From the Washington Post:

Alexis, a native of New York City, worked for a company called The Experts, a subcontractor to Hewlett Packard on a federal contract to work on the Navy Marine Corps Intranet network, according to a statement from Hewlett Packard. It was unclear if Alexis was still employed by that subcontractor, or if his work took him to the Navy Yard.

Alexis died at the scene of Monday’s shooting, in which at least 12 other people died. D.C. Mayor Vincent C. Gray said no motive is known.

By Monday afternoon, a portrait of Alexis had begun to emerge. He lived until recently in Fort Worth, where he was seen frequently at a Buddhist temple, meditating and helping out. He was pursuing a bachelor’s of science degree in aeronautics as an online student at Embry-Riddle Aeronautical University.

Alexis is said to have enlisted in the Navy in May, 2007 and graduated from boot camp in Great Lakes, Illinois.  As a reservist, he later served at the Naval Air Station Joint Reserve Base in Fort Worth until being discharged in 2011, according to NBC 5 DFW.

He eventually became an aviation electrician’s mate, a Petty Officer Third Class, who served at the Naval Air Station Joint Reserve Base in Fort Worth until he was discharged on Jan. 31, 2011. While enlisted, Alexis received the National Defense Service Medal and the Global War on Terrorism Service Medal.

Alexis was reportedly arrested in 2010 for discharging a firearm within a municipality, after he fired a shot through the ceiling of his apartment.  He told police at the time that he’d been cleaning the firearm when it accidentally discharged, according to the police report.  Police declined to file any charges in that incident.

Alexis was also reportedly arrested in 2004 over an incident in Seattle, according to the Wall Street Journal:

In a separate incident, Seattle police said Mr. Alexis had been arrested in 2004 for shooting out the tires of another man’s vehicle in an anger-fueled “blackout.” Mr. Alexis told police at the time he had been deeply disturrbed [sic] by events he witnessed during the attack of Sept. 11, 2001. Police said Mr. Alexis’s father said his son had been involved in 9/11 rescue efforts and had post-traumatic stress and anger-management issues.

In a 6:15pm EST update, NPR reported that officials were still trying to determine whether or not a second suspect was involved.

In a televised press conference, D.C. Police Chief Cathy Lanier said people inside the Navy Yard complex are being asked to continue to shelter in place.

This is because police are still trying to determine if a second person was involved in the shooting rampage.

D.C. Mayor Vincent Gray corrected his earlier statement that the second person of interest was seen on surveillance video. He did say that they still searching for a second suspect.

However, reports seem to have died down this evening regarding the possibility of a second shooter, so it’s unclear whether or not that is still an active concern.

Officials have not determined a definitive motive at this time.

There are other reports of additional details that I haven’t included here until such time they’ve been confirmed by officials.