When a serious crime is in progress, lethal force is sometimes necessary. But police officers often face big information deficits when trying to decide whether to shoot a suspect. David Klinger, Professor of Criminology at the University of Missouri-St. Louis, has been there himself, as a police officer in Los Angeles and Redmond, Washington. And he has interviewed over 100 police officers nationwide to learn more. He discusses how group dynamics, fragmentary information, and a sense of urgency create pressure-cooker situations where police sometimes make mistakes – not shooting when they should or shooting when they shouldn’t.