When I was in elementary school a local police officer made regular visits to explain to us what police did. The department always sent Sergeant Cal Bell, a genial African American who showed us the exotic equipment he carried: badge, large flashlight, nightstick, handcuffs, and service revolver. He told us that he liked to be called “Cow Bell,” which we kids thought was hilarious. I asked him if he had ever used his revolver. “No,” he said, “I have never shot it in the line of duty, and I hope I never have to.”

When I was 12, police in an unmarked car stopped a friend and me one evening when we were spraying passing automobiles with our new squirt guns. They confiscated our water pistols, drove us to our homes, hauled us up the front steps, and turned us over to our parents.

My adult encounters with the police include a few traffic tickets, one of which was received while I was wearing a clerical collar. I assumed that the collar would inspire sympathy—it didn’t. Then a few years ago I had a flat tire on my bicycle while riding on Chicago’s lakefront bike path. Two police officers, a young woman and young man patrolling on bicycles, rode up as I was trying, unsuccessfully, to repair my tire. I asked if they could help me return home. “We’ll do better than that,” one said, and they removed the wheel, applied a quick patch, and reinflated the tire. I was grateful.