When a mother of five loses her fourth son to gang violence, Lilly sets out the save the youngest, reopening one of her first cases on the homicide squad.

The 1975 disappearance of an 8-year-old girl who was never found is reinvestigated after a note written by the girl shortly before she vanished turns up. Their friendship rattled many in the predominantly white neighborhood and the girls quickly became targets of hatred.

The 1976 murder of a teen-aged girl is reopened when her father produces a photo of her and a vicious biker gang.

The team re-investigates the 1958 case of a newlywed real estate developer when new evidence suggests his body might have been moved after he was killed.