. >> researchers melissa farley says exposing and arresting johns long overdue. she says criminalizing and studying their behavior is essential to stop trafficking. >> if we want to learn how to stop prostitution, we really need to know a lot about how men think about prostitution, how they make the decision to buy sex. >> anti-trafficking experts believe men will make different decisions and think twice about buying women if other police departments follow san francisco's lead. the shock and shape of first time arrestees like juan ochoa will help many stop what is criminal behavior. >> a letter from san francisco district attorney's office. it outlines a class, which is something you might consider. you can decide whether you want to go to the class. >> sings he has no arrest, he will qualify for first offender program or johns school. >> this is an opportunity to learn from a mistake you've made and not let it happen again. >> instead of jail time, first time johns pay steep fines and spend a day with other arrestees learning about the grim reality behind prost