In the new musical "Waitress," Mueller plays a waitress in a Southern diner set to the music of Sara Bareilles.
Update 3:39 p.m.: 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.
Note: To hear the 3 p.m. interview with WAMU’s Patrick Madden, click the play button below the headline at the top of the page.
Update 2:56 p.m.: Police say a man in a tan, military-style outfit who had been sought in connection with the shooting rampage at the Washington Navy Yard has been identified and is not a suspect or a person of interest in the slayings.
Update 2:16 p.m.: 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.
Update 1:45 p.m.: As many as three gunmen opened fire Monday inside one of the Navy’s oldest buildings, attacking office workers at a heavily guarded military facility in the heart of the nation’s capital. At least six people were killed.
One of the gunmen was dead, and police were searching for two other men believed to have joined in the attack at the Washington Navy Yard. The suspects were reportedly dressed in military-style clothing, including one who had on a beret.
In all, more than a dozen people were shot, at least half of them fatally. It was not immediately clear whether that number included the dead gunman.
The attack unfolded just a short distance from the White House and the U.S. Capitol at a former shipyard that is one of the Navy’s oldest shore facilities.
The building that was targeted was the military’s headquarters for Naval Sea Systems Command, which buys, builds and maintains ships, submarines and combat systems. About 3,000 people work at the headquarters, many of them civilians.
Witnesses described a gunman opening fire from a fourth-floor overlook, aiming down on people in the first-floor cafeteria. Others said a gunman fired at them in a third-floor hallway.
It was not clear whether the witnesses on different floors were describing the same gunman.
As emergency vehicles and law enforcement officers flooded streets around the complex, a helicopter hovered overhead, nearby schools were locked down and airplanes at nearby Reagan National Airport were briefly grounded so they would not interfere with law-enforcement choppers. Less than 2 miles away, security was beefed up at the Capitol and other federal buildings, but officials said there was no known threat.
President Barack Obama mourned yet another mass shooting in the U.S. that he said took the lives of American patriots. Obama promised to make sure “whoever carried out this cowardly act is held responsible.”
Two Navy officials confirmed at least six people had died. The officials spoke on condition of anonymity because they were not authorized to talk about the situation publicly.
Todd Brundidge, an executive assistant with Navy Sea Systems Command, said he and other co-workers encountered a gunman in a long hallway on the third floor. The gunman was wearing all blue, he said.
“He just turned and started firing,” Brundidge said.
Terrie Durham, an executive assistant with the same agency, said she also saw the gunman firing toward her and Brundidge.
“He aimed high and missed,” she said. “He said nothing. As soon as I realized he was shooting, we just said, `Get out of the building.”‘
Rick Mason, a civilian program-management analyst for the Navy, said a gunman was shooting from the overlook in the hallway outside his office.
Shortly after the gunfire, Mason said, someone on an overhead speaker told workers to seek shelter and later to head for the gates at the complex.
Patricia Ward, a logistics-management specialist, said she was in the cafeteria getting breakfast.
“It was three gunshots straight in a row – pop, pop, pop. Three seconds later, it was pop, pop, pop, pop, pop, so it was like about a total of seven gunshots, and we just started running,” Ward told reporters several blocks away from the Navy Yard.
Ward said security officers started directing people out of the building with guns drawn.
One person died at George Washington University Hospital of a single gunshot wound to the left temple, said Dr. Babak Sarani, director of trauma and acute care surgery. A police officer and two civilian women were in critical condition at Washington Hospital Center, said Janis Orlowski, the hospital’s chief operating officer.
Orlowski said the police officer was in the operating room with gunshot wounds to the legs. One woman had a gunshot wound to the shoulder. The other had gunshot wounds to the head and hand.
Update 12:48 p.m.: President Barack Obama is mourning what he called “yet another mass shooting” in the United States that he says took the life of American patriots. Obama promised to make sure “whoever carried out this cowardly act is held responsible.” The Washington Navy Yard is about 3 1/2 miles from the White House.
Update 12:36 p.m.: Authorities say they are looking for two additional suspects in the shooting rampage at the Washington Navy Yard. District of Columbia Police Chief Cathy Lanier says witnesses reported seeing two additional gunmen, both dressed in military-style clothing.
Update 12:03 p.m.: Navy officials say at least 6 people are dead in the Navy Yard shooting.
Update 11:37 a.m.: A federal law enforcement official says the shooter at the Washington Navy Yard has died.
Update 11:07 a.m.: Officials say police are looking into the possibility of a second shooter at the Navy Yard where several people have been reported killed.
Update 10:30 a.m.: President Barack Obama is getting frequent briefings on a deadly shooting at the Washington Navy Yard.
10:25 a.m. via AP: 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.
ROBIN YOUNG, HOST:
From NPR and WBUR Boston, I'm Robin Young.
MEGHNA CHAKRABARTI, HOST:
I'm Meghna Chakrabarti, in for Jeremy Hobson. It's HERE AND NOW. At least 12 people have been killed in a shooting at the Washington Navy Yard in the nation's capital today. Police say an alleged shooter is also dead. The scene of the shooting is located near Nationals Baseball Park. Here's Police Chief Cathy Lanier.
CHIEF CATHY LANIER: Right now we have an impact to the area. Obviously a large part of the area is still on lockdown. We're still asking residents to stay out of the area and remain in your home.
CHAKRABARTI: Three thousand people work at the Navy Yard. Terry Dunham(ph) told ABC News what she saw when a shooter came into her office.
TERRY DUNHAM: He was far enough down the hall that we couldn't see his face, but we could see him with a rifle, and he raised and aimed at us and fired, and he hit high on the wall.
CHAKRABARTI: Joining us on the line is Patrick Madden, who's a reporter with NPR member station WAMU in Washington. And Patrick, what is the latest on - I heard that police have been looking for additional suspects. What do we know about that search?
PATRICK MADDEN, BYLINE: Well actually some new information has just come out in regards to that search. Now initially police said they were looking for potentially two other possible gunmen. Now they are saying that one of the people that they have been looking for, he's been described as a white male in a tan outfit, well, he is no longer considered a suspect or a person of interest. But that means that they are still looking for another individual, another possible shooter described as a black male, around 40 to 50 years old, in olive-style military uniform.
And again, we just had a press conference with Police Chief Cathy Lanier and Mayor of Washington Vincent Gray, and 12 dead, and that includes the gunman. And that figure, that's a lot larger than what people had been reporting earlier in the day. So it sounds like this is very significant casualties in the building.
Also spoke with D.C. Delegate Eleanor Holmes Norton. She is the District's congresswoman. And she said that she does not believe that this is terrorism-related, but Chief Lanier was careful to say during the press conference that they are not - they don't know what the motive of this mass shooting is yet.
CHAKRABARTI: So - but yet a high casualty number. Do we know anything more about the shooter who police have said has been killed?
MADDEN: We don't. I mean, there are reports out there about who this person may potentially be or not be. But as in what happened in the past, some of those reports were quickly retracted. So at this point I'm not - I'm hesitant to say anything other than, you know, they have not confirmed this alleged shooter, the identity of him.
CHAKRABARTI: Completely understandable, as the story has been evolving over the past many hours. But Patrick, you've been - have you spoken to any eyewitnesses or people who have come out of the building? What have they said about what they saw transpired inside?
MADDEN: Yeah, there has been some really harrowing accounts from people that were in there. I spoke with one person who worked on the floor, this is the fourth floor of this military installation, and that's where the shooting took place. And he described just hearing the shots and then heading - basically heading - there was sort of a frantic rush to get out of there.
And he says that he heard from someone else that the shooter at one point was aiming the weapon down into the atrium on the first floor, and there have been other people that have been talking about shootings that took place on the same floor. So it sounds like as more and more people come out to talk about what happened, it's really going to be a very disturbing scene.
YOUNG: Now Patrick, this is a shooting that's taken place on a United States military installation, a very secure facility, I might imagine. Do we know anything more about the security measures in place or questions being raised about how the shooter or shooters even entered the naval yard?
MADDEN: That's a good point. This was a very secure facility, and in fact D.C. has become a very - there's a lot of security wherever you go in the District. Usually you have to show your ID wherever you go. And I talked to several people who said you would have to show your security badge and a security ID to get into this building. So this is not someplace where you could just walk into.
So that's something that they're going to be looking at, and Congresswoman Norton, who plays a very heavy role in sort of federal property in D.C., and there's a lot of these buildings, so she said this is one of the most secure buildings around. So how this happened and sort of what these - what the gunmen or possibly two gunmen were able to - how they were able to do that, they're going to be looking at that very carefully.
CHAKRABARTI: Patrick, in the 15 seconds or so we've got, it's a very crowded neighborhood, as well. How are people in the neighborhood responding to this?
MADDEN: Well again right now it's like a ghost town. There's no one in the street. The police have cordoned off all - a lot of the area. People who work in this area have been told to basically stay where they are, to shelter in place. So again, this is an up-and-coming neighborhood, but right now there isn't anyone sort of out in the street because everyone has been told to stay away.
CHAKRABARTI: Patrick Madden is a reporter with NPR member station WAMU in Washington. Patrick, thank you so much.
MADDEN: Yeah, thanks a lot. Transcript provided by NPR, Copyright NPR.