In the wake of Robert Durst's chilling "confession" in the finale of The Jinx, his missing first wife's brother is speaking out. Jim McCormack said that Durst's claim that he "killed them all" was "absolutely" a confession.

McCormack's sister Kathleen Durst had disappeared from her and Robert's home in Westchester County in 1982. Robert Durst was suspected, but Kathleen Durst's body was never found. In 2000, when the case was reopened by NY authorities, Durst's good friend Susan Berman was named a prosecuting witness (she may have known where Kathleen's body was dumped or even helped). But then Berman was found dead, in her Los Angeles home, shot in the head execution-style.

Durst, 71, was arrested over the weekend and officially charged with Berman's murder yesterday. Producers of The Jinx, a documentary series on HBO that evolved after Durst himself reached out to director Andrew Jarecki about Jarecki's film based on Kathleen Durst's disappearance, say that they had been cooperating with authorities for months and shared details with them. Including the "confession," which was Durst muttering to himself in a bathroom that he "killed them all."

McCormack watched the finale on Sunday, and told the Today Show, "The revelation was like something we‘ve been waiting for 33 years." He added, "I believe that Bob will somehow have an epiphany of conscience, contrary to the advice of lawyers. “I think he’s about ready to say, ‘You know, enough is enough. This is what Kathy would want and this is what I’m going to do.’"

And former Westchester County District Attorney Jeannine Pirro praised The Jinx's producers, "They put together a case, wrapped it up, put a bow on it and sent it to L.A."

A college friend of Kathleen Durst, Ellen Strauss, spoke to the Journal News:

"I feel extremely vindicated after 33 years," Strauss said Sunday, speaking on her cellphone en route to New York where she was scheduled to give an interview on Fox News.

Over the years, Strauss has investigated a number of tips about Kathie Durst's disappearance. She's been a steady source of information to police investigators about the Dursts' troubled marriage.

"It's not going to bring Kathie back," Strauss added. "He may never be arrested for that case. But he will remain behind bars, where he belongs. It's finally come full circle."