extended suicide
n.— «Suicide is usually a solitary act. But in rare cases, people who are depressed and planning to take their own lives—as appears to have been the case with Virginia Tech gunman Cho Seung-Hui—commit what some psychiatrists call “extended suicide.” This usually involves killing family members—fathers are a favourite target—but in a small percentage of cases the victims are strangers or people the slayer barely knew.» —“Revenge, ‘extended suicide’ reasons for rampages” by Anne Mcilroy Globe and Mail (Toronto, Canada) Apr. 19, 2007. (source: Double-Tongued Dictionary)