A Perfect Day (S03E09)

When evidence of the death of aa 4-year-old girl washes up on the New Jersey shore, Rush and the team reopen a 1965 case. A clue leads Rush to inspect hospital records, and the detective discovers the child, Vivian (Zoe Schlagel), was the victim of abuse; however, Vivian was treated under a false name. Luckily, Vivian's doctor remembers the case and gives Rush some valuable information about the child's mother. The team suspects the mother but has a hard time locating her and an even harder time proving abuse because child abuse records weren't kept in the 1960s. (Warner Bros. UK)