Episode 85 of "Cold Case"
s04e16 The Good-Bye Room

When an adopted woman, Barbara, comes to Lilly with information that her birth mother was murdered the day after she was born, the cold case team enters the world of unwed mothers and the maternity homes where they were hidden. Barbara always wanted to know more about her birth mother, Hilary, and begs Lilly to help her find closure. Lilly accepts the challenge and learns about the strangers Hilary was forced to give birth amongst, the people who tricked her into giving up her newborn and the secret that lead to her ultimately death. This case forces Lilly to reexamine her own personal relationship with her mother. Now Lilly must go back in history and find a killer amongst a few hundred young women at the maternity home who would have rather died or killed than to give up their child.