Serial killer's (SK) familiar relations often present a disorganized adherence characterized by the paternal absence and the excessive maternal coldness or over-protection. This familiar diagram, joined to mistreatment situations, could generate different antisocial conducts in the child because of the vacancy of a significant strong figure.

To study, in the SK, the relation between having suffered childhood mistreatment and the sexual aggression to the victims before killing them.

A study is realized between the variables of childhood mistreatment and sexual aggression to the victims. The data has been extracted from 100 protocols of SK with different nationalities elaborated by the unit of analysis of criminal behavioral (University of Salamanca, Spain).

The results show a significant relation between both variables.

It can be confirmed that the SK who have suffered childhood mistreatment sexually attack their victims before killing them while those who did not experiment it during their childhood do not realize that conduct.

The authors have not supplied their declaration of competing interest.