FBI probes how San Bernardino suspects were radicalized

Aired: 12/7/2015 | 0:03:07 | Clip
As investigators probe whether San Bernardino shooter Tashfeen Malik was the driving force behind the rampage that killed 14 people, President Obama sought to reassure the nation Sunday night in an address. The president did not announce any new strategy to defeat the Islamic State, but he did call for greater gun control measures. Gwen Ifill reports.