As she loitered on a Washington, D.C., sidewalk one recent night, a pretty blonde in yellow bellbottoms seemed ready for business. A light blue Dodge slowed down; its driver beckoned: "You want to go for a ride?"
"No," said the girl.
"Come on," said the driver. "I've got money."
When he named a specific act and a price, Sharon Mann whipped out badge No. 3427 and told the stunned sport: "I am a police officer. You are under arrest for soliciting for prostitution." An unmarked patrol car cut off the Dodge's escape route;...