This report considers how the Optional Protocol to the Convention against Torture and other Cruel, Inhuman or Degrading Treatment or Punishment (OPCAT) obligation to designate a National Preventive Mechanism (NPM) could be met in the Northern Territory (NT), specifically in relation to places of detention in the criminal justice system (including prisons, youth detention facilities, police custody and court custody). OPCAT focuses on the prevention of torture and ill-treatment, and if OPCAT is properly implemented, establishing an effective NPM is an opportunity to minimise the human (and financial) cost of the ill-treatment of detainees. The Fellowship investigated overseas best practices in terms of not only OPCAT compliance, but of culturally appropriate oversight, focusing on Indigenous detainees. The model and recommendations proposed in this report are tailored to the unique NT context. Nonetheless, given that all jurisdictions in Australia suffer from the overrepresentation of Aboriginal and Torres Strait Islander people in their criminal justice systems, many of the recommendations contained in this report will be of relevance to, and all of the best practice examples can provide guidance on, effective OPCAT implementation across Australia.