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)

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)