How Do Ordinary People Become Capable of Mass Murder?

On July 13, 1942, 500 ordinary German policemen arrived in Józefów, Poland, with orders to murder its Jewish residents. Their commander offered them a way out. What happened in that forest, and how did Reserve Police Battalion 101 become responsible for the deaths of 83,000 Jews? Their story raises uncomfortable questions about obedience, peer pressure, and the choices people make when no one stops them.