Organized aggressive behavior usually committed by members of adolescent gangs. Street violence is a public health problem in more than 800 of the largest US cities, where as many as 35 percent of high school dropouts and 5 percent of elementary school children are affiliated with street gangs. Membership in a street gang increases the person’s risk of violent death by 60 percent. Firearms are used in 80 to 95 percent of all gang related homicides.