The story, which wll be updated, specifies that one of the gunmen is black, but not in the headline:

Police say 2 gunmen have killed 4, injured 8 on grounds of Washington Navy Yard By Carol Morello, Peter Hermann and Maggie Fazeli Fard, Updated: Monday, September 16, 11:31 AM E-mail the writer

Here's the relevant description, buried far down in the story, although one shooter is still at large:

Two Navy yard employees interviewed on CNN said they were fired on in a hallway by a gunman they described as a tall black man.

A woman who gave her name as Terry Durham said that as she and co-workers were evacuating, she saw a man down the hall raise a rifle and fire toward them, hitting a wall. “He was tall. He appeared to be dark-skinned,” she said.

“He was a tall black guy,” said her co-worker, Todd Brundage, who is black. “He didn’t say a word.”

The phrase " who is black" here means that Mr. Brundage has permission to say that someone is black.

Two points

• A large number of active shooters are black—and a large number of blacks are Muslims, like the Washington Snipers. See Jezebel: "Have You Noticed That White Dudes Keep Mass Murdering People?" No, We've Noticed You Promoting It
• American soldiers, sailors, and Marines are disarmed by orders of the high command on all bases.  No one has gun to fire back with, and even guards with rifles may not have ammunition. See Diversity Is Strength! It’s Also...Unarmed American Soldiers Dying In Afghan “Green On Blue” Shootings, where this policy is, incredibly, applied to Afghanistan, but it was also in place in Fort Hood.