Aaron Alexis had valid pass to Navy Yard when he unleashed fatal attack

Washington Navy Yard shooter Aaron Alexis had “legitimate access to the Navy Yard” through his contracting work and used “valid pass” to get onto the site, according to FBI Assistant Director Valerie Parlave. 

Investigators believe gunman Alexis, 34, acted alone when he opened fire at the Washington Navy Yard, officials said at a late Monday night press briefing, before identifying seven of the 12 victims fatally shot by the 34-year-old navy reservist.

Alexis died amid a standoff with police.