Science of Interrogation

How do you crack the toughest criminals, psychopaths and pathological liars, cases where no forensics tie the criminal to the crime? The stakes are always very high in a criminal interrogation, get it wrong and a killer can go on killing or an innocent person goes to jail. This is the story of the techniques and science and how they have been applied in real-life cases, using actual police interrogation footage as illustrations. We reveal the exciting new frontiers of lie detection. Can thermal imaging of the face detect tell tale signs of lying? (Source: National Geographic Channel)