I dealt with school violence before it was fashionable and funded. To me, any child killed anywhere, anytime, is a huge tragedy. But decades ago, when children were killed in the inner city of Cleveland, you probably never heard about them. When the killings moved to suburbs such as Columbine, they became national news. The Newtown shootings shocked the United States like no other school violence. Now, school violence prevention is front-page news. Working with school safety for more than 30 years, I have tried to help schools and communities keep our youth safe and healthy so that they can learn more and live better. Here are several lessons that I have learned.