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Unanswered questions: Who was Aaron Alexis?

Officials know the name of the gunman who killed 12 people and wounded eight others at the Washington Navy Yard Monday: Aaron Alexis, a 34-year-old Navy vetera
Aaron Alexis - 09/16/2013
This undated cell phone photo provided by Kristi Kinard Suthamtewakul shows a smiling Aaron Alexis in Fort Worth, Texas. The FBI has identified Alexis, 34,...

Officials know the name of the gunman who killed 12 people and wounded eight others at the Washington Navy Yard Monday: Aaron Alexis, a 34-year-old Navy veteran from Fort Worth, Texas. But his motive and much of his personal history remain a mystery to officials. Alexis was dead by the time the incident ended, and some questions may never be answered.

"We don't have any reason at this stage to suspect terrorism," DC Mayor Vincent Gray said at an early evening press conference, "but certainly it hasn't been ruled out."

Many of Alexis' friends and family were surprised by his brutal actions. "This comes as a complete shock," Algernon Alexis, the gunman's father, told Reuters.

Alexis' brother-in-law Anthony Little, speaking outside the family's Brooklyn, NY, home, said the family is "distraught" about the shooting. The suspected gunman's mother, Cathleen Alexis, was being questioned by the FBI.

Alexis arrived at the Navy Yard carrying only a shotgun, which investigators say he bought just last week at a gun dealer--Sharpshooters--in Lorton, Virginia, about 20 miles from Washington.

They believe that he then picked up two other weapons as he began the shooting spree, taking one of them from a police officer he shot.

When he was killed, authorities recovered three weapons--the shotgun, a handgun, and an AR-15-style assault rifle.

Some friends described Alexis as a good-natured person, who frequently attended a Buddhist temple in Fort Worth and helped out there. One former roommate from Texas, Oui Suthamtewakul, reacted in disbelief, telling NBC News that Alexis "could not be the shooter." Suthamtewakul said he didn't think Alexis harbored any ill-will for the military or the government at large.

The Washington Posts reports, however, that Alexis had been discharged by the Navy after being arrested in a shooting incident. According to biographical data released by the Navy, Alexis enlisted on May 5, 2007; he held the rank of Aviation Electrician's Mate 3rd Class and had been awarded a National Defense Service Medal and a Global War on Terrorism Service medal. The Dallas Morning News reports that Alexis served in the Navy Reserve for four years and was never on active duty.

The shooting incident that may have led to his discharge from the Navy occurred in 2010, when Fort Worth police found that Alexis had fired a shot into the ceiling of his apartment, narrowly missing his upstairs neighbor. Alexis told the reporting officer that "he was trying to clean his gun while cooking and that his hands were slippery," according to the officer's report. Alexis told the officer that the gun discharged accidentally. He was not charged for the incident, but an anonymous Navy official told the Washington Post that it contributed to his discharge from the Navy, along with "a pattern of misconduct."

The neighbor told the officer “she is terrified of Aaron and feels that this was done intentionally." Other friends have noted a aggressive side in Alexis. One said he was "obssessed" with violent online "first-person shooter" games.

But an acquaintance from a Texas Buddhist temple Alexis frequented did not consider him a threat to others.  “I would not have been surprised to hear he had committed suicide," J. Sirun, an assistant to the monks at the temple, told the Washington Post. "But I didn’t think he could commit murder.”

After leaving the Navy Reserve, Alexis was hired by a subcontractor to HP Enterprise Services called "The Experts," to refresh equipment used on the Navy Marine Corps Intranet (NMCI) network. Hewlett Packard said in a statement Monday afternoon. (They did not say whether Alexis was currently employed by the company.) That employment apparently gave Alexis access to the military base. In its statement, HP said it is cooperating fully with law enforcement as requested.

Anyone with additional information about the shooter is asked to contact the FBI's Washington, DC, office at 1-800-CALLFBI.

Rachel Maddow reported on the gunman's background and the still unanswered questions. Watch: