Although it is well-known that infanticide (murder of child< 1year) is typically for young women and libericide (murder of child≥1year) for older melancholic women, comprehensive differences between these two kinds of murderers remain little-known. Our objective was to describe their demographic, clinical and criminological differences.

We collected 41 psychiatric expert examinations in criminal cases of child murder between 2000 and 2005 and compared, after sex-matching, those responsible for infanticide (n=16) and libericide (n=25).

Compared to perpetrators of infanticide, subjects responsible for libericide were older (24 and 33 respectively, p=0.012), and had a psychiatric history (35% versus 71%, p=0.005) and convictions for violence towards others (6% versus 29%, p=0.022). A the time of the crime, 77% of libericide perpetrators were suffering from a psychotic, depressive, cognitive or personality disorders while only 53% of perpetrators of infanticide were ill (p=0.024). Although there was no significant difference in regard of the circumstances of the act or the gender of the victim, we found that head trauma, suffocation and drowning were the most frequent means of infanticide while libericide perpetrators used more active methods such as shooting, strangulation and striking (p=0.007) in a dynamic of homicide-suicide. Finally, it has to be noted that the perpetrators of libericide were more often unfit to plead than the perpetrators of infanticide (p=0.067).

Our results confirm the relevance of Resnick's typology of child murders, distinguishing infanticide and libericide which different criminological dynamics are fundamental for medico-legal orientation and capacity to plead.