Criteria for homicide and suicide on victims of extended suicide due to sharp force injury.

This report is about the findings in association with the extended suicides of nine victims killed by sharp force. All victims were killed by sharp force. The perpetrators were predominantly the parents, the victims their children. Regarding the criteria for differentiating self-inflicted injuries from injuries inflicted by another person, the victims' injuries presented patterns usually found solely in suicides. Thus eight of nine cases presented tentative and hesitation injuries, in three of five cases areas of injury covered by clothing had been exposed beforehand. Despite extremely narrow intercostal spaces in children, injuries to the bones in thoracic stabbing were avoided more often than not (four of seven cases). Only the criterion "defence injury" occurred nearly as often as in homicide victims (three of nine cases). The psychopathology of extended suicide can explain this pattern. The perpetrator's motive is characterised by his pseudoaltruistic belief to save the loved ones from a world that is in his opinion unacceptable. A fusion or integration of the victim into the perpetrator's own self is based on an identity problem. Physical interrelation of forces between perpetrator and victim restricts the victim in his defence and presents an important prerequisite for acquiring the patterns of described injuries.