Updated 4:49 p.m. ET
Authorities confirm that the deceased Navy Yard shooter is 34-year-old Aaron Alexis.
Updated 3:17 p.m. ET
Washington Mayor Vincent Gray: “We have no known motive at this stage.”
Updated 3:05 p.m. ET
Chief Cathy Lanier of the Metropolitan Police Department of the District of Columbia gives descriptions of the suspects and praises the heroic actions of the department and United States Park Police.
Updated 2:05 p.m. ET
At least ten people were injured in the shooting. Authorities believe that one of the shooters is deceased.
Updated 1:31 p.m. ET
Vice President Biden comments on the shooting, saying “a tragedy has occurred” and that he is praying for the safety of military and police personnel involved in the investigation.
Updated 1:20 p.m. ET
A spokesperson for the George Washington University Hospital says the center received the first gunshot wound victim, who is now deceased.
Updated 1:08 p.m. ET
President Obama says that the shooters will be held responsible for the “cowardly act.” As the investigation continues, Obama wants federal and local authorities to work together.
Updated 12:39 p.m. ET
Chief Medical officer Janis Orlowski from MedStar Washington Hospital Center confirms details on three shooting victims and speculates that the weapon used “had to be a semi-automatic, because all victims described rapid succession gunshots.”
Updated 12:46 p.m. ET
Witnesses recall the shooting, saying they heard three shots followed by four more. One Navy Yard employee describes one of the shooters, whose face was covered.