MASS SHOOTING AT WASHINGTON NAVY YARD

   A former Navy serviceman, 34 year old Aaron Alexis, who has a " pattern of misconduct" unleashed a barrage of bullets at the Washington Navy yard on Monday , killing 12 people and injuring eight others.
   He was employed as a military contractor in the Navy yard last week , but worked at multiple Navy offices over the summer, where no report of problems was reported.
   Authorities said Alexis, who was armed with an AR 15, another rifle and a hand gun, was killed after an encounter with security.