Nobody's Child - S4.E17

When Harm views the body of the severely neglected, abused and abandoned young girl, he unexpectedly becomes emotionally involved and decides to call in the help of Teresa Coulter to help him identify the child and find her killer.

After Teresa performs her own autopsy, she uncovers some clues to the girl's history that lead her, along with Harm and Mac, to the last place the child lived -- as well as to a recently released convicted child molester.