A police officer stands guard at the front gate of the Washington Naval Yard September 17, 2013 in Washington, D.C. Aaron Alexis, who had been discharged by the Navy in 2011 after what an official described as a "pattern of misconduct" staged a two-hour rampage Monday at the Washington Navy Yard, killing 12 people before being shot to death by law enforcement officials. (Olivier Douliery/Abaca Press/MCT)
A police officer stands guard at the front gate of the Washington Naval Yard September 17, 2013 in Washington, D.C. Aaron Alexis, who had been discharged by the Navy in 2011 after what an official described as a "pattern of misconduct" staged a two-hour rampage Monday at the Washington Navy Yard, killing 12 people before being shot to death by law enforcement officials. (Olivier Douliery/Abaca Press/MCT) MCT
A police officer stands guard at the front gate of the Washington Naval Yard September 17, 2013 in Washington, D.C. Aaron Alexis, who had been discharged by the Navy in 2011 after what an official described as a "pattern of misconduct" staged a two-hour rampage Monday at the Washington Navy Yard, killing 12 people before being shot to death by law enforcement officials. (Olivier Douliery/Abaca Press/MCT) MCT

Site of Navy Yard Shooting off limits

September 20, 2013 3:13 PM