Judge Jeanine Pirro has searched for 15 years for the truth behind the disappearance of Robert Durst's first wife, Kathleen McCormack Durst. 

National interest in the wealthy real estate heir, and the three suspected murders linked to him, spiked earlier this year during the HBO special, "The Jinx."

In a new Fox News special, Robert Durst and My Quest for Justice, Judge Pirro brings us a riveting look at the Kathie Durst case. 

As a district attorney for Westchester County, Pirro re-opened the 1982 case and quickly learned that Mrs. Durst was a battered woman.

Durst was a 29-year-old fourth-year medical student when she went missing. Pirro was granted an exclusive interview with Kathie Durst's best friend, who has since passed away. 

Gilberte Najamy said she remembers comforting Kathie after the repeated beatings by Robert. 

"I would drive to the city from Connecticut because she was afraid he was coming back. She hesitated to go to the hospital because she was a medical student and it was embarrassing," she said.

Najamy said Robert was "intimidated" by the fact that Kathie was going to become a doctor and "wouldn't need him."

"She would call me in the middle of the night and say, 'He just woke me up. He's showing me a gun and he's telling me that I'm not gonna finish medical school,'" Najamy recalled.

In 1981, after years of abuse, Kathie Durst asked for a divorce. Najamy said that Kathie never got to the point of going after Robert's money.

"She didn't want a lot. She was gonna open a children's clinic. She was gonna be OK on her own," she said. 

Najamy said she last saw her friend alive at a dinner party at her house in Connecticut on the night of January 31, 1982.

She remembers that her family members at the small gathering could all hear Robert screaming at Kathie on the other end of the phone. 

"When she left my house, she turned to me and said, 'Gilberte, promise me if something happens to me tonight, you'll check it out, you won't let him get away with it. I'm afraid of him!'"

Watch the interview above, and catch the re-airing of "Robert Durst and My Quest for Justice," Sunday at 9p/12a ET on Fox News Channel.

Also, check out Judge Pirro's new book, He Killed Them All.

Robert Durst: The Definitive Story That You Didn't See on TV