Conventional forms of homicide are a byproduct of social interaction; their incidence increases on weekends, holidays, and other times of more intense social activity. This chapter covers homicide, including the rare occurrences of mass and serial killing, aggravated assault, rape, domestic violence, abuse of the elderly, sibling violence, and the often overlooked area of business, government, and professional violence. Injuries are often brought about by a failure to take proper precautions or by deceit in validating tests, as with new drugs. Organized crime is also covered, as organized criminals engage in activities such as extortion, drug trafficking, money laundering, and protection rackets in which for a certain payoff they will “protect” a merchant from their own willingness to wreck his or her store and from predation by other mobsters.