Jasper Ames is Rosie Larsen's ex-boyfriend. Privileged and smug, he parties at his jet-setting parents' Mercer Island weekend home when they're out of town. Jasper's tweaker friend Kris Echols hints to Sterling that Jasper and Rosie hooked up after the Halloween dance, but when Stan Larsen arrives at the Mercer Island home looking for his daughter, he instead finds a middle-aged woman in the bedroom. While being interviewed by Sarah, Jasper contends that he and Rosie "hooked up for like two seconds." Jasper's father Michael demands that Sarah stop questioning his son, and later smacks Jasper across the face when he attempts to explain matters. Jasper's previous transgressions include an arrest for auto theft.
Kris Echols accuses Jasper of telling the police that he was at the Halloween dance. A cell phone that Bennet Ahmed confiscates from a student contains video footage showing a masked Jasper forcing himself on a young woman dressed like a witch, then peeling off his mask and switching places with Kris, who was filming the encounter.