Today marks 40 years since the disappearance of Kathie Durst, the wife of the late Hudson Valley real estate heir Robert Durst.

Earlier this month, Robert Durst, who was the main suspect in her disappearance, died from medical complications while serving out a life sentence for the murder of his best friend Susan Berman.

Prosecutors suspect that Berman was killed because she knew information about Kathie Durst's disappearance.