Real estate heir Robert Durst just cut a deal with a New Orleans federal court, pleading guilty to illegal possession of a .38 caliber revolver.

As part of the arrangement, he will be sentenced to 85 months in federal prison. Durst will be transferred to an LA federal prison by Aug. 18 to face charges for the death of former friend Susan Berman, the New York Times reports.

The estranged son of real estate titan Seymour Durst, Robert broke ties with his family in 1994 when his father and uncle picked his younger brother Douglas to take over the family business.

Durst's life is shrouded in mystery, beginning with his first wife Kathleen's 1982 disappearance. Authorities suspect Durst killed Berman—a friend and magazine writer—to keep her from revealing what she knew about the 1982 incident.

With a net worth of $100M, Durst has been able to afford some of the best defense lawyers available. However, things started unraveling once the HBO special The Jinx: The Life and Deaths of Robert Durst aired last February, revealing his alleged misdeeds.

"What the hell did I do?" Durst is heard saying in the documentary, seemingly unaware his mic was still on. "Killed them all, of course." Nonetheless, his high-priced legal team argues a lack of evidence against Durst.

"They’ve got a TV show and 15-year-old evidence that wasn’t good enough back then,” lead attorney Dick De Guerin says, “and certainly isn’t good enough now.” [NYT]