Newly released security camera footage shows Washington Navy Yard shooter Aaron Alexis running through the hallways at the Navy Yard with a sawed-off shotgun.

In the chilling closed-circuit video, Alexis is shown pulling into the compound in his car, calmly entering the facility with his shotgun stowed in a backpack and then prowling the hallways with the weapon out.

Al Jazeera's Rosiland Jordan reports from Washington DC.

Source: Al Jazeera