Fans of “Dateline NBC” regularly tune in to the show to watch a good murder mystery. Tonight, the NBC program will offer a potboiler of a different sort.

In an exclusive interview with NBC NewsKate Snow, Andrea Constand, a woman seen by many as being at the center of the criminal case against comedian Bill Cosby, discusses her assault at the hands of the entertainer. ”I was in and out of consciousness,” she tells Snow. “Inside I was so– I was crying out inside, in my throat, in my mind, for this to stop. And I couldn’t do anything.”

“Maybe you have seen pictures of her, but you have not heard her before in her own words unless you were seeing her in that courtroom,” says Snow, in an interview. “The only people who have heard her are the ones who have heard her in that courtroom.”

Snow has been covering the allegations against Cosby for some time, even interviewing 27 of his accusers in a single room for the venerable NBC newsmagazine, and she says she hoped Constand would come forth. Thanks to longstanding work by Marianne Haggerty, a veteran NBC News producer, the news unit was in touch with one of Constand’s attorneys and managed to make a connection. “She hasn’t talked to anyone, understandably,” notes Snow. “But if she was going to talk, I wanted to be that person. Form there, it was in her hands.” Viewers, says Snow, will see a person who is “calm, serene and incredibly centered.”

The interview marks the latest in a series of presentations by “Dateline” that break with its usual format. Regular viewers gravitate to the program to watch Keith Morrison, Josh Mankiewicz, Dennis Murphy, Andrea Canning and others take them through the prosecution of various murders. In recent weeks, however, viewers have seen Savannah Guthrie interview former USA Gymnastics National Team Coordinators Bela and Martha Karoly about the broadening sex assault scandal that has gripped that sport, or seen Lester Holt interview rapper Meek Mill after his release from prison.

“’Dateline’ is always a mix,” says Liz Cole, executive producer of the show. “We do many mysteries on Friday nights, and that’s the main thing you will continue to see, but when the opportunities present themselves for us to do these pieces where we can showcase unique reporting and exclusives, we will always be up for those.”

The show has long had coverage of events in the headlines, notes David Corvo, “Dateline’s” senior executive producer, whether it has been in-depth coverage of the Boston bombing or President Barack Obama’s final TV interview in office. “Whether we are looking at a traditional murder mystery or something a little bit unorthodox, viewers know enough to say, ‘These guys don’t let me down,’” he says.

Still, the show has to change its traditional format to accommodate different sorts of stories. “Dateline” typically employs a “six-act” structure when taking viewers through the ins and outs of a crime, notes Snow. In tonight’s broadcast, viewers will find out about Constand’s childhood and background in addition to hearing from her on the news of the moment. “This is a unique story. This is a woman who has not spoken in 13 years about what she has been through. It creates a different set of circumstances and we can tell the story a little differently,” she says.

For Snow, the interview is one of a number of stories she has covered while tracking sexual harassment. She says she tries to be “sensitive and respectful” when interviewing victims and tries to “draw them out without being intrusive or overstepping.” She had to ask Constand about some of the allegations made about her by Cosby’s defesne team as part of the report.

“Dateline” will continue to break away from its murders when circumstances warrant, says Corvo. Many producers on the team have worked together for more than 20 years and have a comfort level when assigning resources to various stories. “We can muster the troops if we need to,” he adds.