LOS ANGELES—Robert Durst, the wealthy New York real estate heir and failed fugitive who was dogged for decades with suspicion in the disappearance and deaths of those around him before he was convicted last year of killing his best friend, has died. He was 78. Durst died of natural causes Monday in a hospital outside the California prison where he was serving a life sentence, according to the Department of Corrections and Rehabilitation. Durst had been held in a hospital lockup in Stockton due to a litany of ailments. Durst was convicted in September of shooting Susan Berman at point-blank range at her Los Angeles home in 2000. He was sentenced Oct. 14 to life in prison without parole. Durst had long been suspected of killing his wife, Kathie, who went missing in New York 1982 and was declared legally dead decades later. But only after Los Angeles prosecutors proved …