Documentary following the investigators who must hunt for the truth and bring the guilty to justice. When a man fatally stabs a suspected thief outside his Suffolk home, detectives must untangle whether it was self-defence or something much darker. In Hertfordshire, a woman's car is found engulfed in flames and police records show she has been reported for drug dealing. Officers uncover a chilling pattern of stalking, deceit and control that leads back to her ex-boyfriend, who is already under a protection order. But who is telling the truth?