Minnesota trial highlights officers' duty to intervene

This is the fourth week of the trial of three former officers who were on duty with Derek Chauvin when he murdered George Floyd in 2020. The officers are on trial for their role in his death and over questions about what they should have done at the time. Christy Lopez, who oversaw investigations of police departments at the Justice Department from 2010 to 2017, joins William Brangham to discuss.