She was last seen at her South Salem home in 1982 and the man she married -- long a suspect in her disappearance -- has been jailed since 2015.
On Thursday, Kathie Durst was officially declared dead.
While Robert Durst, a Scarsdale native and millionaire real estate heir, has never been charged in connection with his wife Kathie Durst's disappearance, he did appear to confess to killing her and others in a 2015 HBO documentary, which reported that a microphone caught him saying, "What the hell did I do? Killed them all of course."
Robert Durst is currently awaiting trial in California, where he's been charged in connection with the 2000 shooting death of Susan Berman , a longtime confidant.
Kathie Durst was 29 and a medical student when she went missing more than 35 years ago.
The decision to declare her dead was made Thursday by Surrogate's Court Judge Nora Anderson, according to the New York Post, which said that the move allows Kathie Durst's family to pursue a multimillion-dollar lawsuit against Robert Durst -- the last person to see her alive.