Bimodal classification of homicide: homicides are classified as, reactive (affective) aggression: aggression that is impulsive, unplanned, immediate, driven by negative emotions, and occurring in response to some perceived provocation. Instrumental (predatory) aggression: aggression that is premeditated, calculated, and motivated by some goal (e. g. , to obtain money: reactive homicide occurs more often among relatives, and instrumental homicide among strangers. Interpersonal features of psychopathy were associated with instrumental violence: social deviance features of psychopathy were associated with reactive violence, lifestyle features of psychopathy were associated with both types of violence. In non-familial homicides of children and youth, stabbing is the most common method of death. Female serial murderers: many female serial killers appear to be either (cid:862)(cid:271)la(cid:272)k (cid:449)ido(cid:449)s,(cid:863) those (cid:449)ho kill for fi(cid:374)a(cid:374)(cid:272)ial gai(cid:374), or (cid:862)a(cid:374)gels of death,(cid:863) (cid:374)urses (cid:449)ho kill their patie(cid:374)ts. Mass murderers: school shootings are examples of mass murder. In the classic mass murder, an individual goes to a public place and kills strangers at that location.