Finding the roots of Dylann Roof’s radical violence

Aired: 6/22/2015 | 0:12:03 | Clip
The mass shooting in Charleston isn’t just an isolated event, but can be seen as part of a troubled history of racial hatred and violence in the United States. What makes someone embrace racist ideology and what can be done to stop it? Gwen Ifill talks with Richard Cohen of the Southern Poverty Law Center, former FBI special agent Gregg McCrary and Paul Butler of Georgetown University Law Center.