The study examined the challenges affecting the performance of Police Reservists in Loima Sub-county to understand why insecurity was thriving despite continued recruitment of the Reservists. The study aimed at examining the performance of the Reservists; identify the challenges affecting their performance; and come up with appropriate measures to address the challenges. The study established that all the Reservists were male, aged between 35 and 44 years, at primary level of education, married and economically poor. The study identified and prioritized legal/policy gaps based on their level of threat to effective Reservists performance. These include lack of remunerative allowances, lack of clear guidelines on recruitment and deployment, command and control, training, medical cover, injury and life compensation and role ambiguity. Additionally, the Reservists' level of training in security and policing was very low, especially on community policing, human rights, intelligence collection, peace building and conflict resolution and protection of crime scenes. Training on weapons was a bit better due to frequent use and training.