This paper describes how the radical concept of maternal perversion first presented by Estela Welldon (1988) informs the psychotherapeutic assessment and treatment of female inpatients within forensic services and of women in the community who commit acts of violence. It presents a model of the psychology of female violence that the author describes as ‘crimes against the body’. The paper offers clinical evidence for Welldon's model of female perversion in forensic settings and provides an extended clinical illustration of psychotherapeutic work, when the therapist was pregnant, with a woman who killed her child.