Valerie Parlave, FBI Assistant Director of the D.C. Field Office, said at a press conference shortly after 10 p.m. that suspected gunman Aaron Alexis “had legitimate access to the navy yard as the result of his work as a contractor, and he utilized a valid pass to gain entry.”

Questions had swirled throughout the day over how Alexis had gained access to the naval base with a gun, especially after violent events in his past were brought to light.

Police also believe that Alexis, who was killed in an engagement with police, acted on his own.  Metro Police Chief Cathy Lanier said that, after spending much of the day searching for a man in an olive drab military-like uniform, police had ruled out the possibility of a second shooter.

The police lifted the “shelter in place” order that had been in effect for residents of the area for most of the day, clearing them to move freely around the area.

Follow Alexis on Twitter