3. Man's Best Friend?

In 1989, 4-year-old April Loveless was found dead in the backyard of her Texas home. Her mother Debbie Loveless and step-father John Miller told police that she was attacked and killed by neighborhood dogs, but the injuries on her body didn't match their account of what happened. Investigators believed April's wounds were slashing injuries, consistent with a knife wound. John and Debbie were found guilty of murder and sentenced to life in prison. Five years later, the parent's prayers were answered when a forensic scientist saw something in the crime scene photographs that had been missed the first time around.