it was police officers, firefighters, and other first responders. in parkland, florida we saw teachers and coaches put themselves between the bullets and students. >> student students it. studen. it is natural to think about what we would do. >> it's aver everyday hero. it's a hero in training. reporter: this is a professor at stanford university. he's phone for the study of the psychological effects of prisoners and guards and how good people can become evil. now days he's focused on the opposite. whether ordinary people can be inspired and trained to become everyday heroes. >> i'm here today to say the answer is yes.