For the purposes of this meta-synthesis, "filicide" is defined as "the killing of a son or daughter older than 24 hours." Resnick's classifications are based on motive, which were determined from his interviews with perpetrators and those close to the perpetrators. Almost half of the filicides examined by Resnick were categorized as "altruistic," involving the killing of children that a parent did not want to leave on their own after the parent's planned suicide or to relieve a child of real or imagined suffering. Resnick's other categories of motives are acute psychosis, an unwanted child, accidental filicide, and spousal revenge. Scott believed a clinical assessment should avoid criterion of motive and use instead the source of the impulse to kill, such as the child's behavior or a displacement of anger. D'Orban used Scott's categories to identify women at risk for killing their children. His categories of mothers at risk for filicide are battering mothers, mentally ill mothers, mothers with children less than 24-hours old, retaliating women, women with unwanted children, and mothers with suffering children. Bourget and Bradford suggest a system of classification that encompasses various types of clinical situations; and Guileyardo, Prahlow, and Barnard developed 16 filicide subtypes based on motives and causes. The sources for their data were expanded from previous researchers to include findings of medical examiners. Bourget and Gagne went one step further in emphasizing the role of impulsivity and neurotransmitter activity in psychiatric illness and gender differences in parental filicide. Implications for prevention and future research are drawn from the meta-synthesis. 33 references