WASHINGTON (AP) — The Navy on Thursday ordered an in-depth investigation into the Washington Navy Yard shooting and the events that led up to it, including a detailed look at the shooter, his mental health background and whether any adverse information was ever reported to the service about him.

Navy Secretary Ray Mabus outlined the order in a memo describing what will be a parallel investigation to the FBI’s criminal probe. The investigations will address lingering questions about whether the contractor that employed Aaron Alexis warned the military of concerns about his mental stability. Alexis gunned down 12 people in building 197 at the Navy Yard on Sept. 16 before being killed in a shootout with police.