Complex sentence: Schmid and his friends took Rowe to the desert, where Schmid and Saunders murdered her, before murdering Alleen, Schmid told Saunders to rape her first, but he couldn't do it, while Mary French was waiting in the car and listening to the radio.
Split into simpler sentences: Schmid and his friends took Rowe to the desert, where Schmid and Saunders murdered her. While the murder occured, Mary French was waiting in the car and listening to the radio.