Violence is the use of physical force so as to injure, abuse, damage, or destroy. Other definitions are also used, such as the World Health Organizations definition of violence as "the intentional use of physical force or power, threatened or actual, against oneself, another person, or against a group or community, which either results in or has a high likelihood of resulting in injury, death, psychological harm, maldevelopment, or deprivation. "Internationally, violence resulted in deaths of an estimated 1.28 million people in 2013 up from 1.13 million in 1990. However, global population grew by roughly 1.9 billion during those years, showing a dramatic reduction in violence per capita. Of the deaths in 2013, roughly 842,000 were attributed to self-harm (suicide), 405,000 to interpersonal violence, and 31,000 to collective violence (war) and legal intervention. For each single death due to violence, there are dozens of hospitalizations, hundreds of emergency department visits, and thousands of doctors appointments. Furthermore, violence often has lifelong consequences for physical and mental health and social functioning and can slow economic and social development. In 2013, of the estimated 405,000 deaths due to interpersonal violence globally, assault by firearm was the cause in 180,000 deaths, assault by sharp object was the cause in 114,000 deaths, and the remaining 110,000 deaths from other causes.Violence in many forms can be preventable.
Despite this, force is used routinely against juveniles by police. In 1974, the US Department of Justice assumed primary responsibility for delinquency prevention programmes and created the Office of Juvenile Justice and Delinquency Prevention, which has supported the "Blueprints for violence prevention" programme at the University of Colorado Boulder. Public health
The public health approach is a science-driven, population-based, interdisciplinary, intersectoral approach based on the ecological model which emphasizes primary prevention. Rather than focusing on individuals, the public health approach aims to provide the maximum benefit for the largest number of people, and to extend better care and safety to entire populations. The public health approach is interdisciplinary, drawing upon knowledge from many disciplines including medicine, epidemiology, sociology, psychology, criminology, education and economics. Because all forms of violence are multi-faceted problems, the public health approach emphasizes a multi-sectoral response. It has been proved time and again that cooperative efforts from such diverse sectors as health, education, social welfare, and criminal justice are often necessary to solve what are usually assumed to be purely "criminal" or "medical" problems. The public health approach considers that violence, rather than being the result of any single factor, is the outcome of multiple risk factors and causes, interacting at four levels of a nested hierarchy (individual, close relationship/family, community and wider society) of the Social ecological model. From a public health perspective, prevention strategies can be classified into three types:

Primary prevention – approaches that aim to prevent violence before it occurs.