What are police looking for in the school shooting case in Madison, Wisconsin?

Authorities said a teen student opened fire at a Christian school in Madison, Wisconsin on Monday, killing one student, a teacher and injuring several others. Police identified the suspect as a 15-year-old girl who seems to have died of a self-inflicted gunshot wound. CBS News correspondent Ian Lee reports.

What are police looking for in the school shooting case in Madison, Wisconsin?
Authorities said a teen student opened fire at a Christian school in Madison, Wisconsin on Monday, killing one student, a teacher and injuring several others. Police identified the suspect as a 15-year-old girl who seems to have died of a self-inflicted gunshot wound. CBS News correspondent Ian Lee reports.