Presumption of Innocence

Homicide prosecutor David Brunelle faces the most difficult case of his career. An innocent young girl is murdered in a heinous, unforgivable way. The only evidence against the killer is the full confession of his accomplice--another young girl he also victimized. But the accomplice is charged with the murder as well, which means that she has the right to remain silent. And she's so scared of the killer, she refuses to take a deal to testify against him. Brunelle can't just let the murderer walk, but how can he get a conviction when he has no admissible evidence and the killer is protected by the presumption of innocence?