Sterling Beaumon, Molly Hagan and Dominic Flores have joined the cast of Law & Order: True Crime — The Menendez Murders, NBC’s limited series from Dick Wolf and Rene Balcer that premieres in the fall.

The eight-episode first season will focus on the infamous case of Lyle Menendez (Gaston Villanueva) and Erik Menendez (Gus Halper), brothers who were convicted in 1996 of murdering their parents seven years earlier. After a mistrial and deadlocked juries — there was one trial but two separate juries, one for each brother — the brothers later were re-tried and convicted of two counts of first-degree murder and sentenced to life without parole.

Beaumon will play Glenn Stevens, a friend of Lyle’s from Princeton and a college hockey player, Glenn became Lyle’s business partner after the murders, managing the first of a chain of restaurants. Hagan will portray Joan Vandermolen, Kitty’s older sister, she is a woman of Midwestern reserve. Flores is Henry Llano, a cousin of Lyle and Erik, he is regularly seen interacting with the other family members, but was regarded as a loudmouth by the late Jose Menendez.

Beaumon recently appeared in an episode of Hulu’s anthology series Dimension 404 and previously recurred on Longmire and Powers. He’s repped by APA, manager Bernard Kira, and Gang Tyre Ramer & Brown.

Hagan has recurred on the CW’s Jane the Virgin and iZombie and had a supporting role in Clint Eastwood’s Sully. She’s repped by Patino Management Company and AEFH.

Flores was previously in Our Brand is Crisis with Sandra Bullock and The Meddler with Susan Sarandon. He’s repped by Luber Roklin Entertainment and The Beverly Hecht Agency.