Season 4. DCI Roz Huntley is determined to catch a serial killer. The culprit, a 24-year-old is on the run and Roz has so for led a fruitless investigation. AC-12 investigate after forensic evidence suggests that this man might be innocent! Is Roz and her team hiding something? The DCI will make a decisive move in order to stop her life from crashing.
Starring Thandie Newton, Martin Compston, Vicky McClure