The first wife of real estate heir Robert Durst has been officially declared dead 35 years after she was last seen.

A New York judge set the date of death for Kathleen Durst at Jan. 31, 1987, exactly five years after her 1982 disappearance from Westchester County in New York.

The ruling from Surrogate's Court in Manhattan was dated March 24. It was first reported in the New York Post.

Robert Durst was the lead suspect in the disappearance of Kathleen Durst in 1982

Robert Durst has long been suspected in the death of his wife who was 29-year-old at the time but he was never criminally charged.

Durst pleaded not guilty to the murder of his close friend Susan Berman and has said he had nothing to do with the disappearance of his wife, whose body has never been found.

Kathleen's strange disappearance was featured on the HBO docuseries 'The Jinx' along with Berman's murder and the killing and dismemberment of Durst's Texas neighbor.

In the final scene episode of the show, Durst is not aware his microphone is on when he says: 'What the hell did I do? Killed them all, of course.'

He was extradited to California to be tried for Berman's murder in 2016.

On February 14, 2017 prosecutors questioned whether or not Durst called the dean of the New York medical school and had someone pose as his wife in 1982 to say she could not make her doctor's appointment.

Robert Durst appears in the Airport Branch of the Los Angeles County Superior Court after pleading not guilty to murdering Susan Berman

Kathleen Durst was declared dead in March of 2017 with her date of death as Jan. 31, 1987. Now, her family can pursue a civil case against Robert Durst

The 73-year-old Durst is charged with murder in the 2000 killing of Berman in Los Angeles. She was killed execution-style, allegedly because of what she knew about the unsolved death of Durst's spouse two decades earlier.

Berman reportedly was planning to speak with investigators about Kathleen Durst's suspected slaying.

The declaration of death for Kathleen Durst allows her siblings to pursue civil litigation against Robert Durst.