This article reviews recent findings in the developmental neurophysiology of children subjected to psychological trauma. Studies link extreme neglect and abuse with long-term changes in the nervous and endocrine systems. A growing body of research literature indicates that individuals with severe trauma histories are at higher risk of behaving violently than those without such histories. This article links these two research areas by discussing how severe and protracted child abuse and/or neglect can lead to biological changes, putting these individuals at greater risk for committing homicide and other forms of violence than those without child maltreatment histories. The implications of these biological findings for forensic evaluations are discussed. Based on new understanding of the effects of child maltreatment, the authors invite law and mental health professionals to rethink their notions of justice and offender accountability, and they challenge policymakers to allocate funds for research into effective treatment and for service delivery.