With shoddy evidence collection and bad police work exposed at trial, Karen's legal team suggests that someone may have killed John inside the house.

As the case sparks a civil war in Boston, some dub Karen 'America's Happiest Murder Defendant.' At trial, humiliating texts shock the courtroom.

Experts debate the cause of John's injuries, and closing arguments begin. Karen anxiously awaits her fate, and the jury delivers an unexpected note.