Robert A. Durst, the scion of a New York real estate dynasty whose life dissolved in a calamity of suspicions over the unsolved disappearance of his first wife, the execution-style murder of a longtime confidante and the killing and dismemberment of an elderly neighbor, died early Monday January 10 2022 as a prisoner in Stockton, Calif. He was 78. Robert Durst was arrested in March 2015 and charged with murder; the family bought out his stake in the business for $65 million in 2006. Over four decades Mr. Durst was suspected of having killed three people: his wife, Kathleen Durst, who vanished on Jan. 31, 1982, after a fight at their home in South Salem, N.Y., and was never seen again; his friend Susan Berman, who was shot in her Benedict Canyon home in Los Angeles in 2000; and Morris Black, a neighbor who was shot in Mr. Durst’s Galveston, Texas, apartment in 2001. There was only one relatively clear-cut case against him. It was the killing of Mr. Black, a 71-year-old cantankerous former merchant seaman. Mr. Durst dismembered the victim and dumped the body parts in Galveston Bay. Arrested on a murder charge, he jumped bail and fled. But in the baffling case that made Mr. Durst a nationally known and deeply distrusted celebrity — the disappearance of his wife, Kathleen, in 1982 — there was for decades insufficient evidence to file charges against him. For years, Ms. Berman, a journalist, had been Mr. Durst’s spokeswoman and staunchest defender in confrontations with reporters and his wife’s family and friends after her disappearance. Yet Mr. Durst was belatedly charged with Ms. Berman’s murder in 2015 in a reinvestigation of her killing, which had occurred 15 years earlier. After his arrest in the Berman case, he was not brought to trial for nearly six years. Held in custody at a medical facility of the Los Angeles Sheriff’s Department, he underwent surgeries for esophageal cancer and fluid on the brain. During the trial, Mr. Durst’s brother Douglas, who oversaw the family’s $8 billion real estate empire, and Nick Chavin, a longtime friend of Mr. Durst’s, were both witnesses for the prosecution. After seven and a half hours of deliberations, the jury on Sept. 17 2021 found Mr. Durst guilty of first-degree murder. He was sentenced in October to life in prison with no possibility of parole. Robert Alan Durst was born on April 12, 1943, in Manhattan, the oldest of four children of Seymour B. and Bernice (Herstein) Durst. His father was the patriarch of a Manhattan office and apartment building empire founded in 1927 by Robert’s grandfather, Joseph Durst, an Austrian emigrant. Robert and his siblings, Douglas, Thomas and Wendy, grew up in the Westchester suburb of Scarsdale, but their comfortable childhood was punctured in 1950 by the death of their mother, who fell or jumped from the roof of their home. Mr. Durst graduated from Lehigh University in 1965 with a degree in economics, but dropped out of postgraduate studies at U.C.L.A.