In this photo obtained exclusively by Channel 4 News, alleged Washington, D.C. navy yard shooter Aaron Alexis is seen celebrating the New Year in Thailand in 2012.

This undated photo provided by Kristi Kinard Suthamtewakul shows Aaron Alexis in Fort Worth, Texas. The FBI has identified Alexis, 34, as the gunman in the, Sept. 16, 2013 shooting rampage at at the Washington Navy Yard in Washington that left thirteen dead, including himself.

People come out from a bulding with their hands up after a shooting happened at the Washington Navy Yard Sept. 16, 2013 in Washington, DC.

A Emergency Response Team vehicle arrives to the scene where a gunman was reported at the Washington Navy Yard in Washington, Sept. 16, 2013.

Map locates the Washington Navy Yard where a shooting occurred and at least 12 people were killed, Sept. 16, 2013.

Aaron Alexis, deceased, is believed to be responsible for the shootings at the Washington Navy Yard, in the Southeast area of Washington around 8:20 a.m. on Sept. 16, 2013.

A family member of a Navy Yard worker who was evacuated during a shooting arrives hoping to find him at a makeshift shelter at the Nationals Park baseball stadium near the naval installation in Washington, Sept. 16, 2013. Police have confirmed that at least 12 are dead and several other wounded.

Unidentified people are seen on Sept. 16, 2013, outside parking lot B of Nationals Park which has been set as a gathering point for families of the Navy Yard shootings in Washington.

A U.S. Capitol Police officer keeps watch on the East Plaza of the Capitol as the investigation continues at the nearby Washington Navy Yard where at least one gunman went on a shooting rampage, Sept. 16, 2013, in Washington.

An official from the Washington Office of the Medical Examiner wheels a body on a gurney out of the emergency room at George Washington University Hospital shortly after it was announced that the first victim of the shooting at the Navy Yard in Washington had died at the hospital, in Washington Sept. 16, 2013. his head.

People exit a building with their hands above their heads as police respond to the report of a shooting at the Navy Yard in Washington, Sept. 16, 2013. At least one unidentified gunman opened fire at the US Navy Yard in Washington on Monday and was at large after killing "multiple" victims and wounding several more, officials said.

Law enforcement personnel respond to a reported shooting at the Washington Navy Yard Sept. 16, 2013 in Washington.

Shooting eyewitness Patricia Ward speaks to the media on M Street, SE near the Washington Navy Yard on Sept. 16, 2013, in Washington.

A police boat and helicopter patrol near the scene of a shooting at the Washington Navy Yard, Sept. 16, 2013, in Washington. At least one gunman opened fire inside a building at the Washington Navy Yard, and police have confirmed that at least 12 people are dead and several others wounded, including a law enforcement officer.

Scene where an unidentified man opened fire in the Washington Navy Yard, Sept. 16, 2013, in Washington.

Police and first responders arrive on the scene where a man opened fire in the Washington Navy Yard, Sept. 16, 2013, in Washington.

Police block off the area around the Washington Navy Yard where a shooter opened fire, injuring several people, Sept. 16, 2013, in Washington.

People help a man on the ground at the Washington Navy Yard in Washington, Sept. 16, 2013. Police blocked off the area around the Navy Yard where a shooter opened fire, injuring several people.

Police respond to the report of a shooting at the Washington Navy Yard, Sept. 16, 2013, in Washington.

Police respond to the report of a shooting at the Navy Yard in Washington, Sept. 16, 2013. A gunman shot and wounded at least 10 people at the headquarters building at the U.S. Navy Yard in Washington.

Police work the scene on M Street, SE, in Washington near the Washington Navy Yard, Sept. 16, 2013. Police say at least 10 people are injured after a shooting at the Navy building in Washington.

Police work the scene on M Street, SE, in Washington near the Washington Navy Yard, Sept. 16, 2013. Police say at least 10 people are injured after a shooting at the Navy building in Washington. Police and emergency crews gathered Monday morning outside the Naval Sea Systems Command Headquarters building, where the shooting was reported.