Washington Metropolitan Police Chief Cathy Lanier speaks at a news conference about the shootings at the Washington Navy Yard, while outside of the FBI Washington Field Office, in Washington, on Tuesday, Sept. 17, 2013, the day after the shootings at the Navy Yard.
As the investigation continues, we're learning more about how emergency officials responded to the Navy Yard attack.
D.C. Police Chief Cathy Lanier says years of training and planning lead to yesterday's "nearly flawless emergency response."
"Two minutes after the call was dispatched, we had officers at the gates arriving at the scene," Lanier says. "Within 7 minutes, we had officer at the building entering the building to engage and active shooter as shots were actively being fired."
The FBI confirms that suspect Aaron Alexis entered the building with a shotgun, and may have gained access to a handgun while inside the building.
Lanier says officers were engaged with the shooter for more than half an hour before the final shots were fired.
An FBI spokesperson says Alexis came to D.C. on Aug. 25, and had been staying in local hotels — most recently at a Residence Inn in Southwest Washington.