Robert Durst, a New York real estate heir and multimillionaire, was sentenced on Thursday to life in prison without chance of parole for the murder of his best friend in California more than two decades ago. The 78-year-old Durst was convicted last month in Los Angeles Superior Court of first degree murder in the death of Susan Berman. Berman, the daughter of a Las Vegas mobster, was Durst’s longtime confidante. The Los Angeles jury found he was guilty of having shot Berman, 55, in the back of the head at her Beverly Hills home in December 2000. The jury had also found Durst guilty of the special circumstances of lying in wait and killing a witness, which carries a mandatory life sentence without the possibility of parole. Prosecutors said that Durst had sought to prevent Berman from incriminating him in the reopened investigation of the disappearance of his wife Kathleen McCormack, who went …