At 15, Samantha Walker was lured into prostitution on the streets of Toledo, Ohio, then taken against her will to Atlanta. What makes her story different from thousands of others is that she testified against one of the men who paid for sex with her, helping to send him to prison. But at 18, just weeks after the trial, she took an overdose of prescription drugs for depression and died.

More than 300,000 children are being sexually exploited in the United States, according to a study by the University of Pennsylvania. Many of them end up in Atlanta, which authorities say has become a hub for prostitution in part because its busy airport makes it a destination for men seeking sex. For law enforcement authorities in Atlanta, Walker’s courage and suicide have made her a heroine, and they’re using her story to spur new efforts to crack down on child predators.

Atlanta Mayor Shirley Franklin is leading a drive against child prostitution under the banner of “No more, not in my city.” Prosecutors have started to bring felony rather than misdemeanor charges against men who use child prostitutes. “When a child is involved, we can no longer politely call these men ‘johns.’ They are panderers, child molesters, and felons,” said one Atlanta official.