Gun violence isn’t simply a social problem or a law enforcement matter–it’s a threat to public health. That’s the approach taken by the Johns Hopkins Center for Gun Policy and Research, which crunches the numbers behind gun violence and helps form public policy to stem the bloodshed. The center has been involved in a Milwaukee effort to tamp down gun violence after the city’s homicide rate spiked in 2005, reports John Hopkins Public Health (Fall 2008). Research showed that one of every four guns seized by city police came from one gun shop, Badger Guns and Ammo. Armed with this data, city officials convinced Badger’s owners to take steps to discourage “straw purchases,” in which legal buyers pick up guns for illegal buyers. “Our ultimate goal,” says center codirector Jon Vernick, “is to see our research used by policy makers to reduce the unacceptable toll of gun violence in the United States and worldwide.”