The movie might have been bearable as purely a work of fiction. However, it was based on a murder committed by a pedophile, who seduced and killed the two victims. In fact, he assaulted the daughter at their final picnic before stabbing her through the heart.
To have a movie portray this as not only a vehicle for a heroic young man as victim, but as a "dark comedy" is unconscionable. It would have worked much better as a close-to-the-facts drama. Surely the real story was strange enough.