Over the course of 69 minutes, Alexis killed 2 people and terrorized thousands of employees of Naval Sea Systems Command, firing indiscriminately from a shotgun he had legally purchased two days earlier and a handgun he had taken from a security guard after mortally wounding the guard. He would also get into multiple shooting engagements with responding law enforcement officers, seriously injuring a Metropolitan Police Department (MPD) officer. In his final confrontation with police, Alexis ambushed and fired upon another MPD officer. Fortunately, the officer was saved by his protective vest and was able to return fire, killing Alexis and ending his rampage.
On September 16, 2013, hundreds of police, fire, and emergency medical personnel from several different agencies responded to the Navy Yard after receiving news of the shooting. Officers relied upon their training, experience, and instincts to run into an unfamiliar and massive building, towards the gunshots and certain danger, in order to stop the gunman from taking more lives.
This after-action report was prepared and released by the Metropolitan Police Department under the authority of Chief Cathy Lanier.
Among the findings and recommendations in the after action report:
Military base emergency centers and civilian police agencies should establish cooperative protocols for how to share 911 information before an incident occurs to avoid overlap and confusion.