On the basis of systematic assessments, UNODC can help governments build more accessible, accountable and effective criminal justice systems and identify areas that require reforms e.g. the accountability and oversight of the police service, the management of prisons, and how to accommodate the needs of vulnerable groups such as women, children and juveniles. UNODC works with countries in transition and with United Nations peace operations to help restore and build justice systems. Because of the transnational nature of organized crime, UNODC encourages and supports international cooperation among judicial and law enforcement authorities including through mutual legal assistance and extradition.