The Naga officer, Ben Longkumer, started working with the UNMIS in November 2010. He was initially posted at Maridi in Western Equatoria state and worked as the operations officer in-charge, personnel officer and the team leader of the team site. He was actively involved in developing and strengthening the capacity of the South Sudan Police Services (SSPS) by advising them on policy, planning, and legislative development to enable the SSPS to protect civilians.
When South Sudan got its independence in July 9, 2011, Longkumer was rolled over to the new mission- United Nations Mission in South Sudan (UNMISS). He was posted at Bentiu State HQ, Unity State as the deputy state advisor in Unity State and was responsible for overall direction, supervision, management and administration of UN police personnel.