CBS Evening News | Andre Simons runs an FBI unit that works to stop shootings before they happen, and in the past year his behavioral team has tackled 150 cases -- not one resulting in violence

Andre Simons runs an FBI unit that works to stop shootings before they happen, and in the past year his behavioral team has tackled 150 cases -- not one resulting in violence. When the unit gets a heads up about threatening behavior, analysts work to re-direct the subject to mental health treatment, monitoring or custody. Bob Orr reports. Air Date: Dec 16, 2013