Innocent (1) - S3.E1

Creegan is on sick leave when a man who he helped convict for the murder of his wife and another woman is released from prison. Creegan was always unsure of the conviction, until the man made a full confession. However, when the murders start again, Taylor brings the suspect straight back into custody. Creegan then leads a one-man show to prove he was right. The suspect then commits suicide following interrogation, and a fourth victim is found shortly afterwards.