MICHEL MARTIN, HOST: For the rest of this hour, we’re going to be looking at policing in the United States. It’s not the only subject of national protests that have been playing out over the last few weeks, but it’s certainly at the heart of it. We’re going to hear from police who tried to point out misconduct in their own departments. We’ll take a look at the powerful police unions that protect and advocate for officers and who are also blamed for standing in the way of change. We’re going to trace how policing has evolved through U.S. history and how it’s been portrayed on television and why that matters. But we’re going to start with news from Atlanta, where the city’s police chief has resigned less than 24 hours after Atlanta police killed a 27-year-old black man outside a fast food restaurant. Erika Shields had been a member of the Atlanta Police Department for 25 years and had led the force since 2016. Mayor Keisha Lance Bottoms announced the chief’s resignation this afternoon.