Over the years, the relative peace that placed Nigeria among the most secure nations in the West African sub-region has been eroded and the country has suddenly metamorphosed into an abode of serial bombings, hostage-taking, kidnapping, armed robbery, cold-blooded murders and ethno-religious conflicts. The increasing nature of the indices of insecurity in the country is not only disturbing but also questions the effectiveness of the Nigerian security architecture, especially that of the Nigerian Police which is primarily saddled with the responsibility of providing security to the people. This has led to a series of debates and arguments on how best to reform the Nigerian Police in order to reposition it to meet the new wave of security challenges confronting the country. It is against this backdrop that this chapter attempts a discussion of the performance level of the Nigeria Police in the management of internal security in the wake of the challenge for the struggle for sustainable peace and the safety of lives and properties in the country. The chapter argues that the performance of the police, especially with regard to civil relations, is significantly influenced by the colonial legacy of its establishment. The security agency is highly centralized making it difficult for swift and dynamic decision-making needed to confront the trajectories of conflict and security challenges. The chapter identifies a number of challenges hindering the effectiveness of the Nigerian Police which include manpower shortage and elite policing, poor public perception, the issue of politicization, and overly centralized and non-meritocratic leadership. The chapter concludes that there is high prospect for the Nigerian Police to be effective if the challenges facing the institution are holistically addressed.