A 1979 Surgeon General's report made one of the first explicit links between public health and law enforcement; it identified violent behavior as a significant risk to health. Four years later, the Centers for Disease Control and Prevention (CDC) established the Violence Epidemiology Branch, which later became the Division of Violence Prevention. The public health approach to addressing problems that threaten public health has four basic elements: define and monitor the problem; identify risk and protective factors; develop and test prevention strategies; and ensure widespread adoption of prevention programs that have proven effective. Some of NIJ's early work in public health involved a partnership with the CDC. In the 1990s, the agencies worked together on the National Violence Against Women Survey, which sought a better understanding of intimate partner violence and victims' use of medical services and the criminal justice system's involvement. Over the years, this partnership has continued to provide research on the consequences of intimate partner violence, which is now measured by the National Intimate Partner and Sexual Violence Survey. Recently, NIJ and the CDC jointly published "Changing Course: Preventing Gang Membership," a book that identifies and discusses principles for preventing youth from joining gangs. For the last 3 years, NIJ has also been a sponsoring organization for the Forum on Global Violence Prevention in the Institute of Medicine at the National Academies. To date, the Forum has held six 2-day workshops, bringing together hundreds of participants. This article also provides some examples of links between public safety and law enforcement in East Palo Alto, CA; Milwaukee, WI; and Cardiff, Wales. 9 notes