Speck of Evidence (S03E11)

On September 17, 1984, in a suburb of Tucson, Arizona, eight-year-old Vicki Hoskins left home on her pink bicycle to mail a letter for her mother. She never returned, but her slightly damaged bicycle was found nearby. Investigators turned to forensic science, in the hope it would tell them not only what happened to Vicki, but also who was responsible. (Prime Video)