Little Lucas Hernandez has been missing for months and now his father is arrested on a domestic violence charge. The Kansas 5-year-old's stepmom was already jailed on charges of endangering another child, but no one is yet facing charges relating to Lucas's disappearance. Nancy Grace has been closely following the investigation into what happened to boy. She is joined in this episode by  Missing Pieces Network founder Kim Martin, Juvenile Judge and lawyer Ashley Willcott, and reporter Leigh Egan. Also in this episode, the family of Tyler Lumar wants to know what led to the 22-year-old's death from injuries suffered in jail after he was mistakenly arrested. Chicago police took Lumar into custody two years ago on an outdated warrant two days before he was found unresponsive in his cell. Nancy Grace looks at the case with private investigator Vincent Hill, psychologist Caryn Stark, and RadarOnline.com reporter Alexis Tereszcuk.