This Report presents the findings of research into self-inflicted deaths (SID) in custody amongst 18–24 year olds in National Offender Management Service (NOMS) custody in England and Wales. This research was commissioned by the Harris Review into Self-Inflicted Deaths In Custody Amongst 18–24 Year Olds, and was undertaken by RAND Europe and the Prisons Research Centre, Institute of Criminology, University of Cambridge.