Tenderness (2009) on Netflix

Three lives. Buffalo detective Lt. Cristofuoro, whose catatonic wife is in hospital, takes a special interest in Eric Komenko, a juvenile who killed his parents and will be freed on his 18th birthday. So has Lori Cranston, 15 or 16, her body fully developed and the object of lust by her boss and her mother's new boyfriend. She keeps a scrapbook about Eric, and when he's released from custody, she hides in the backseat of his car, insisting he take her with him on a trip toward Albany where he's planning to meet a girl. Cristofuoro is certain Eric will kill again, so he follows. It's clear early on that Cristofuoro's probably right, but what's Lori's motivation?