SAS Death Squads Exposed: A British War Crime?

British special forces killed hundreds of people on night raids in Afghanistan. The SAS say they were insurgents who were posing an imminent threat. But were some of the shootings executions? Panorama investigates a series of raids where people were shot dead after they surrendered to British troops. Reporter Richard Bilton uncovers new evidence and tracks down eyewitnesses who say they saw unarmed Afghans being killed in cold blood.