The correct answer is Assailant.
The costs of violence are to the victim, to the society and to the assailant.
The possible cost of violence to a victim is permanent injury and death, to the assailant is feeling guilt and face criminal charges. Costs of violence to the society is that it makes people in the society to live with fear and health care system which is costly.
Some of the risk factors for violence include, exposure to media violences, poverty and family violence, drug abuse and membership in gangs.