Federal Bureau Of Investigation

9_252013_navy-yard-shooting-2-48201.jpg

This image from video provided by the FBI, shows Aaron Alexis enters Building 197 at the Navy Yard at 8:08 a.m., on Monday, Sept. 16. Alexis, a 34-year-old ex-Navy reservist and IT contractor, fatally shot 12 people inside the Washington Navy Yard building. (FBI via associated press)

9_252013_navy-yard-shooting-78201.jpg

** FILE ** Aaron Alexis was captured on video moving through the hallways of Building 197 at the Washington Navy Yard on Sept. 16 carrying a Remington 870 shotgun. FBI officials said he did not specifically target his shooting victims and was "prepared to die." (FBI via Associated Press)

9_192013_ap6878232098118201.jpg

FBI Director James B. Comey said of the Washington Navy Yard gunman, "It appears to me that he was wandering the halls and hunting for people to shoot." (associated press)

Aaron Alexis AP yellow shirt.jpg

The FBI has identified Aaron Alexis, 34, as the gunman in the Monday, Sept. 16, 2013 shooting rampage at at the Washington Navy Yard in Washington that left thirteen dead, including himself. (AP Photo/Kristi Kinard Suthamtewakul)