This research explores the prevalence of adverse childhood experiences (ACEs) among a cohort of young people engaged in Garda Youth Diversion Programmes (GYDP), and the implications for professionals working with these young people. The report begins with an overview of the relevant literature in relation to trauma experiences of people within the criminal justice system and professional responses to trauma, namely trauma-informed practice approaches. The literature review is followed by an outline of the methodology including how ethical concerns were mitigated through the research. Following this, is a profile of the young people in this research group, followed by the primary findings section which presents information on trauma type, prevalence and an analysis by various characteristics such as time in care, employment status and other demographic information. The final two chapters – a thematic analysis of focus groups undertaken with youth workers and Juvenile Liaison Officers, and the discussion section, explore implications of the research findings. The report ends with a recommendation endorsed by the various stakeholders engaged in the research process.