'The ongoing investigation into those who helped him cover up her murder continues': Robert Durst dies in prison

Robert Durst, 78, died Jan. 10 at a state prison in Stockton, California after being suspected of killing his wife, Katherine Durst.

Attorney Chip Lewis said he died from natural causes.

"We understand that his death was due to natural causes associated with the litany of medical issues we had repeatedly reported to the court over the last couple of years," Lewis said.

An attorney for Kathie's family said an investigation into who helped Robert cover up the murder is still ongoing.

“On Jan. 31, 2022, the 40th anniversary of Kathie's murder, we will provide a further update. In the interim, please say a prayer for Kathie and his other victims,” the attorney said in a statement to ABC 13.

Durst was convicted last September of murdering friend Susan Berman in Los Angeles in 2000. A court sentenced him to life in prison without parole.

Once an heir to the New York-based Durst Organization, much of Durst's adulthood had been pockmarked with suspicion in the disappearance and deaths of those connected to him. He was the prime suspect in the unsolved 1982 disappearance of his wife, Katherine. While on the run from the law following Berman's shooting death, he went to Galveston, where he was implicated in the 2001 death of his neighbor, Morris Black. Durst was acquitted of Black's demise in 2003.

“The last conversation that I had with Kathie was a very powerful conversation and as she was leaving my house, she turned to me and said ‘Gilberte, promise me if something happens to me, you'll check it out. I'm afraid of what Bobby might do,’” Gilberte Najamy, Kathie’s friend, told ABC.

This year will mark 40 years since Katherine McCormack Durst went missing. An attorney representing her family said in a statement that the investigation into her death will continue despite her former husband's death.