An overrepresentation of stepchildren as victims of filicide has been explained as a consequence of ‘discriminative parental solicitude’. The idea being that Darwinian selection has favoured parental love and concern only for biological children, and when such parental feelings are absent, as in stepparents, conflicts with a child could easier escalate to lethal violence. An alternative explanation for this overrepresentation of stepchildren is that risk factors for filicide, such as criminal behaviour and mental health problems, are more prevalent in stepparents. This study focused on paternal filicide in Sweden and investigated (i) if stepchildren are overrepresented as victims of filicide compared with biological children, (ii) if filicides are committed in a context that implies a ‘conflict with the child victim’ and (iii) if stepfathers and biological fathers differ in characteristics associated with filicide risk. The analyses showed that stepchildren were overrepresented as victims compared with children of fathers in families with two biological parents and this overrepresentation was even higher in young children. Children of single biological fathers and children of non-residential biological fathers were also overrepresented as victims of filicide. Less than 20 percent of the filicides were committed in the context of a ‘conflict with the child’ and in these cases only stepchildren were overrepresented as victims. In the population at large, both stepfathers and single biological fathers had higher rates of mental health problems, violent criminality and illegal possession of drugs compared with fathers in families with two biological parents.