Defense Secretary Chuck Hagel and senior military leaders are reviewing not only security measures at all military installations, but also whether security clearances for its contractors are sufficient.
OutFront: Republican Congressman Michael McCaul - he's the chairman of the house homeland security committee.
In the hours after the Navy Yard massacre, Washington D.C. Police Chief Cathy Lanier became the face of Washington's response and investigation.
But the path to becoming DC's top cop hasn't been easy or straightforward.
Our Jessica Yellin is Outfront with Lanier's story.
Troubling questions are being raised about how the suspected D.C. shooter Aaron Alexis ended up as a military contractor in the oldest Naval facility in the country.
As we reported, Alexis was a former Navy Reservist with a troubled military career, who was discharged in 2011 because of a "pattern of misconduct."
He was then hired by a contractor, giant Hewlett-Packard and given security clearance with the Navy.
This seems shocking and it prompted Republican Senator Susan Collins to say these latest developments really make her "question the kind of vetting contractors do."
OutFront: Former Navy SEAL, and sniper Cade Courtley and Tim Clemente, former FBI Counterterrorism Expert.
As each hour passes we are learning more about Aaron Alexis - the military contractor who officials say managed to breach security at the Washington Navy Yard and kill 12 people.
Bud Kennedy is OutFront. He knew the alleged shooter. He's also a columnist with the Forth Worth Telegraph.