By Welner, M. In: Payne-James et al. Encyclopedia of Forensic & Legal Medicine, 3rd Edition Elsevier 2025 (1) pp 360-370
Intro: The United States Supreme Court in Miller vs. Alabama (2011) provided sentencing judges the discretion to determine whether such convicted killers under age 18 warrant a life sentence. The rationale was that as the brain may be maturing at the
time of the murder, an offender may evolve to outgrow one’s personal adversity, and come to pose diminished risk to the community.
Since the Miller decision, mental health professionals routinely inform sentencing courts about a defendant’s maturity, psychosocial challenges, and future risk. Proper assessment focus should draw from data in multiple psychosocial domains, and the study of the crime itself, to distinguish elements of immaturity as well as more sophisticated criminal deviance. This chapter includes a guide for individualized assessment of the relevant domains of criminal maturity and offender prognosis, drawing on forensic psychiatry, forensic pathology, developmental psychopathology, and criminology research, as well as best practices of forensic assessment.
