U.S. law enforcement officials told the AP that 34-year-old Aaron Alexis had been suffering a host of serious mental issues, including paranoia and a sleep disorder. He also had been hearing voices in his head, the officials said.
The officials, who spoke on condition of anonymity, said Alexis had been treated since August by the Veterans Administration for his mental problems. The Navy had not declared him mentally unfit, which would have rescinded a security clearance that Alexis had from his earlier time in the Navy Reserves.
Last month, Alexis called police in Newport, R.I., saying he switched hotels three times because he heard voices in the walls and ceilings. Police documents show he wanted to file a harassment report because the voices were trying to keep him awake. Newport authorities contacted Naval station police but it's unclear if the military took any action.
His father says Alexis suffered from post traumatic stress disorder after helping to rescue people during the Sept. 11 attacks, and often had flares of rage.
Alexis had been hired as an IT contractor by the Navy and had just started working at the Naval Yard this week. Authorities say he had security clearance to enter the facility.
For unknown reasons, he went on a shooting rampage on Monday, shooting at employees as they were eating breakfast and coming into work. In total, 13 people were killed including Alexis, who was gunned down by police.
Investigators say they have not found a manifesto or other writings to explain Alexis' motive.
According to the FBI, Alexis, born in Queens, N.Y., had a rifle on him when he entered Building 197 Monday morning. Officials said he apparently obtained a handgun once inside.
No indication of a possible motive is known at this time. Authorities say they will examine all possible motives, including terrorism.
Friends say Alexis had recently converted to Buddhism. He was a former full-time Navy reservist from 2007 to 2011.
Officials said Alexis had a string of misconduct problems during his nearly three years in the military, but he received an honorable discharge.
Authorities said he had bouts of insubordination, disorderly conduct and was sometimes absent from work without authorization. The offenses occurred mainly when he was serving in Fort Worth, Texas, from 2008-2011, and were enough to prompt Navy officials to grant him an early discharge through a special program for enlisted personnel.
Officials said the bad conduct was enough to make it clear Alexis would not be a good sailor, but not enough to warrant a general or less-than-honorable discharge.
Alexis was most recently stationed at Naval Air Station Fort Worth where he worked for the fleet logistics support squadron No. 46, according to Lt. Cmdr. Sarah Blansett, a Navy spokesman.
FBI officials said Alexis arrived in the D.C.-area back on Aug. 25, staying at local hotels. He had been staying a Residence Inn since Sept. 5.
Alexis' friends say he had worked for other Navy offices over the summer and may have been frustrated about his pay.
"I know he expressed a lot of frustration and a lot towards that. That's when I first started hearing statements about how he wanted to move out of America. He was very frustrated with the government and how as a veteran he didn't feel like he was getting treated right or fairly," said Kristi Suthamtewakul, Alexis' friend.
Friends say Alexis was often frustrated about not being able to find full-time work. Over the summer, he allegedly called a friend while working as a contractor at several Navy offices.
"He was wondering if I could help him out a little bit financially, because they were slow to pay. The company did not pay him what they said they were going to," said Michael Ritrovato, a friend.
Friends say along with being a contractor, Alexis often spent hours playing military-style video games and even started missing work because of his video game habit. At the same time, friends describe Alexis as a kind man who often volunteered as a waiter at local Thai restaurant in Fort Worth, Texas.
Alexis had several run-ins with the law. He was arrested in 2004 in Seattle for shooting out the tires of a car. He called it an anger-fueled blackout.
He was also arrested in 2010 in Forth Worth for firing a gun through the ceiling of an apartment - he said it was an accident.
Meantime, flags are flying at half staff in our nation's capital in honor of the 12 people who were gunned down in Monday's mass shooting.
In memory of the victims, Secretary of Defense Chuck Hagel and senior Department of Defense leaders placed a wreath at the U.S. Navy Memorial Plaza Tuesday morning.
The Navy Yard reopened Tuesday for essential personnel.
At the time of the rampage, Alexis was an employee with The Experts, a company that was a Defense Department subcontractor on a Navy-Marine Corps computer project, authorities said.
The company released the following statement on Tuesday:
"The Experts would like to express our deepest condolences and sympathies regarding the incident that occurred at the DC Naval Yards. We are cooperating fully with the FBI and other authorities in relation to the investigation on the suspect.
At this time, we can confirm that the suspect had been employed by The Experts for approximately six months over the last year, during which time we enlisted a service to perform two background checks and we confirmed twice through the Department of Defense his Secret government clearance. The latest background check and security clearance confirmation were in late June of 2013 and revealed no issues other than one minor traffic violation."
A Pentagon official confirms that Hagel will order a review of all security and access at all military facilities around the world. It could be formally announced as soon as Wednesday.
In addition to those killed at the Navy Yard, eight people were hurt, including three who were shot and wounded, according to the mayor. Those three were a police officer and two female civilians, authorities said. They were all expected to survive.
Officials said the victims who died ranged in age from 46 to 73 years old. No victims were active duty military personnel; all are described as civilians and contractors:
- Michael Arnold, 59
- Sylvia Fraiser, 53
- Kathleen Gaarde, 62
- John Roger Johnson, 73
- Frank Kohler, 50
- Kenneth Bernard Proctor, 46
- Vishnu Pandit, 61
- Arthur Daniels, 51
- Mary Francis Knight, 51
- Gerald L. Read, 58
- Martin Bodrog, 54
- Richard Michael Ridgell, 52
The lead investigation has since been taken over by the FBI. A law enforcement official told ABC News that the FBI was questioning the suspect's father, mother and sister.
Anyone with information regarding the shooting was urged to call (800) CALL-FBI. Anyone wishing to find information on family members was urged to call (202) 433-6151.
ABC News and The Associated Press contributed to this report.