Investigators release details and video of Navy Yard massacre.
Survivors of shooting rampage resume work as investigation continues.
Man forced to barricade himself in office during Monday's shooting spree describes his ordeal.
Cathleen Alexis issues statement to victims of her son's shooting spree at the Washington Navy Yard.
Investigators are learning more about Aaron Alexis and what his motivation for shooting more than a dozen people, but many questions still remain.
Navy Yard gunman shot out construction worker's tires during dispute in Seattle in 2004.
Woman caught up in Navy Yard shooting sends terrified texts to family members in North Dakota as events progress.