UPDATED 3:27 p.m.
The D.C. mayor says 13 people have died in the shooting rampage, including the gunman.
Mayor Vincent Gray said at a news conference Monday afternoon that the shooter was among the dead. Officials say the gunman has been identified as 34-year-old Aaron Alexis.
Earlier in the day, authorities had been looking for two other people who may have been involved in the shooting. One of those people has been identified and ruled out as a suspect.
However, Gray says investigators are still searching for a third individual wearing an olive-green, military-style uniform to determine if he was involved.
Gray says a motive has not yet been determined.
A hospital official says a police officer and two civilians wounded in the shootings at the Washington Navy Yard are expected to survive.
The shooting rampage left at least 12 people dead.
But the three being treated at Washington Hospital Center are expected to survive. Janis Orlowski, the hospital's chief operating officer, detailed their injuries at a Monday afternoon news conference.
The police officer was still in surgery to treat gunshot wounds to his lower extremities, though Orlowski says he is expected to make a good recovery.
A second victim has a shoulder wound and also is expected to recover.
Orlowski says the third victim being treated at the hospital was shot in the head, but the bullet did not penetrate her skull.
Federal law enforcement officials say the man accused in a shooting rampage at the Washington Navy Yard that left at least 12 people dead has been identified as Aaron Alexis.
The two officials spoke Monday to The Associated Press on condition of anonymity because they were not authorized to speak publicly.
One of those officials says Alexis was a 34-year-old from Texas. He is believed to have a criminal record there and to be a holder of a concealed carry weapon permit.
That official says Alexis is believed to have gotten into the Navy Yard by using someone else's identification card. It is not yet clear if that individual was an accomplice or if that person's ID card was stolen.
Police say at least 12 people have died in the shootings at the Washington Navy Yard.
D.C. Police Chief Cathy Lanier said during a news conference Monday that 12 people were confirmed dead.
Lanier says people are being told to stay in their homes and out of the area as authorities search for two other possible suspects. One of the shooters has died.
The police chief says officers are searching for two other people with firearms wearing military-style uniforms.
She says there is no indication of a possible motive at this time.
Two Navy officials say at least six people have died in a shooting at the Washington Navy Yard.
The officials spoke on condition of anonymity on Monday because they were not authorized to discuss the situation publicly.
A Defense Department official and a federal law enforcement official have said a shooter had died, though it was not immediately clear how.
Police are also looking into the possibility of a second shooter.
As many as 10 were wounded.
Officials say at least one shooter has died at the Washington Navy Yard, where several people were killed and as many as 10 were wounded.
A federal law enforcement official and a Defense Department official said Monday morning that a shooter had died. Both spoke on condition of anonymity because they were not authorized to discuss the ongoing investigation.
Two other officials have said they are looking into the possibility of a second shooter at the Navy Yard.
Two officials say police are looking into the possibility of a second shooter at the Washington Navy Yard where several people were killed.
A Defense Department official and a law enforcement official spoke on condition of anonymity Monday because they were not authorized to discuss the ongoing investigation.
At least one gunman opened fire inside the Naval Sea Systems Command headquarters, where about 3,000 people work just miles from the Capitol.
Among the wounded was a D.C. police officer, according to a law enforcement official who spoke on the condition of anonymity because the person was not authorized to discuss an ongoing investigation.
At least 10 were wounded.
A Defense Department official says several people have been killed and as many as 10 have been wounded in a shooting at the Washington Navy Yard.
The official spoke on condition of anonymity Monday because the official was not authorized to discuss the matter publicly.
The official also says the shooter is "contained" but not yet in custody.
Earlier in the day, the U.S. Navy said it was searching for an active shooter at the Naval Sea Systems Command headquarters, where about 3,000 people work.
The exact number of people killed and the conditions of those wounded was not immediately known.