Trying to Prevent Violence Via Mental Health Screening

Aired: 9/25/2013 | 0:04:40 | Clip
Revelations about the mental health of Navy Yard gunman Aaron Alexis raises questions about whether better screening processes could have prevented the shooting. Gwen Ifill talks to Barry Rosenfeld of Fordham University about the challenges of identifying on an individual level when someone with mental illness may pose a threat.