Offenses that involve force or the threat of force are defined as violent crimes. Violent crime is composed of four major categories: murder, rape, robbery, and aggravated assault. Violence can be involved in a crime by either being a means to the end, such as in robbery or rape, where the violence aids in committing the crime, or by being the objective or end of the crime itself, as in aggravated assault, murder, or non-negligent manslaughter.