As Liberia began to emerge from civil war in 2003, the warring sides agreed to overhaul the discredited national police service. In the Comprehensive Peace Agreement signed in Accra, Ghana, the parties designated the United Nations as the lead body in rebuilding and reforming Liberia’s civilian police capacity. In a joint effort between Liberian and U.N. police, led initially by U.N. Police Commissioner Mark Kroeker and Liberian Inspector General Chris Massaquoi, reformers vetted and trained a new police service of more than 4,000 officers, established specialized units to combat gender-based violence and high-risk threats, improved internal accountability mechanisms, and began to reverse the sordid reputation for unlawful killings and rape the police had earned during Liberia’s civil war. This case offers insights into the development of the Liberia National Police, one of the successes in post-war Liberia and an uncommon example of successful post-war police reform.