The reckoning after a gunman attacked two mosques in New Zealand, killing 50 people, rings familiar for many Americans, who have seen many school shooters' histories examined in the media in the search for a reason for their violence. Is there anything that can be done to intervene and stop a violent young person before they commit mass murder?

Jim Braude was joined by Nancy Rappaport, associate professor of psychiatry at Harvard Medical School, and Andria Amador, senior director of behavioral health services for Boston Public Schools.