It was a gripping case that was one of the first to draw a daily national audience to a televised criminal trial. Lyle and Erik Menendez were convicted in 1996 of murdering their mother, Mary Louise, a former beauty queen who went by Kitty, and their father, Jose, a music executive, despite defense arguments that the brothers had been sexually molested for years by their father, and had killed out of fear. Now, Roy Rosselló, a former member of Menudo, the boy band of the 1980s that became a global sensation, is coming forward with an allegation that he was sexually assaulted as a teenager by Jose Menendez. The series, “Menendez + Menudo: Boys Betrayed,” based on reporting by the journalists Robert Rand and Nery Ynclan, is largely focused on Mr. Rosselló. He describes an encounter with Mr. Menendez but also recounts separate incidents of sexual abuse that he says were inflicted on him by one of Menudo’s former managers when he sang as part of the group.

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