Forget the old'good cop, bad cop' routine -- soon police may be turning to artificial intelligence systems that can reveal a suspect's true emotions during interrogations. The face-scanning technology would rely on micro-expressions, tiny involuntary facial movements that betray true feelings and even reveal when people are lying. London-based startup Facesoft has been training an AI on micro-expressions seen on the faces of real-life people, as well as in a database of 300 million expressions. The firm has been in discussion with both UK and Mumbai police forces about potential practical applications for the AI technology. The latter are reportedly interested in using the technology as part of crowd control measures, with the algorithm detecting when an angry mob might be forming.