Cooper Koch and Nicholas Alexander Chavez have been cast in Season 2 of Ryan Murphy and Ian Brennan’s “Monster,” Variety has learned. They will play the Menéndez brothers in the Netflix anthology series, which told the story of Jeffrey Dahmer (Evan Peters) in Season 1.

Netflix confirmed the subject and title of “Monsters: The Lyle and Erik Menendez Story” in May. This will be the first of the two additional “Monster” installments that Netflix ordered after “Dahmer — The Jeffrey Dahmer Story” became the streamer’s No. 2 most popular English-language series of all time.

Erik (played by Koch) and Lyle Menéndez (Chavez) were convicted of the murders of their parents, José and Mary Louise “Kitty” Menéndez, in 1996. The brothers eventually confessed, but maintained that they killed their parents out of fear after being abused. Recently, former Menudo band member Rosselló also made sexual assault allegations against José Menéndez, which were explored in...