The third episode of the series looks at Stephen Hough, who raped and killed 15-year-old Janet Commins in 1976. Hough had thought he had gotten away with the perfect murder having fabricated an alibi for his horrific crimes, resulting in an innocent man going to jail. But detectives never gave up; four decades later they made a breakthrough DNA discovery that saw Hough locked away. In 2017 he was convicted for his crimes of manslaughter and rape and was sentenced to 15 years in jail. Hough was only 16 years old at the time of the crime