The 4th Constabulary Regiment was responsible for the northern region's pacification and sweep during the 228 Incident. They also joined forces with other units to "sweep" the Keelung City area. After the martial law was declared on March 10, the 4th Constabulary Regiment was tasked with clearing and pacifying the area north of Hsinchu. The regiment's commander, Major General Zhang Mu Tao, also took on the role of commanding the Northern Pacification District. The original site of the 4th Constabulary Regiment was the Hongji Hospital established by Dr. Lin Qingyue. Later, it was taken over by the Taiwan Governor's Office and renamed the Rehabilitation Institute, which served as a treatment center for opium addicts and drug abusers. After the war, the institute was relocated, and the site was occupied by the 4th Constabulary Regiment.