At age 17 in 1962, he joined the
Nigeria Police Force (NPF) for cadet training, but had to wait a year before this could begin. In 1965, he completed his training with the rank of
Assistant Superintendent of Police (ASP). After a brief stint in Abakaliki, Horsfall was selected to join the
Special Branch; at the time, the top three cadet graduates were selected for posting in either the A Department Force
Headquarters, the
Criminal Investigation Department (CID), or the
Special Branch. Soon after, Horsfall's boss and Special Branch commissioner, J. J. Sullivan, a retired
British Major recognized Horsfall's potential and deployed him to the
Border control unit at
Enugu. At the time, most Nigerian officers in the Special Branch were regarded by the expatriate officers as being more loyal than intelligent. After Sullivan went on retirement leave, his Nigerian successor, T. H. Fagbola, who needed capable Nigerian officers to work with, assigned Horsfall back to headquarters in
Lagos. Soon after, Horsfall attended an intelligence training course in the
United States. While he was there in 1966, the
Nigerian Civil War broke out. Horsfall, from the southern part of the country, returned to Nigeria on the side of the Federal Government. At the time,
General Yakubu Gowon's government had dissolved the country's four regions—Northern Region,
Western region,
Mid-Western Region, and the
Eastern Region—into 12 new states. This was calculated to fragment support for the seceding
Biafran state, which was mostly made up of the Eastern Region and the Mid-Western State. Horsfall's new
Rivers State was formerly part of the Eastern Region, which now sided with the Federal Government in the war. When Horsfall returned from the
United States, the Special Branch was severely short-staffed because of the exodus of easterners to seceding Biafra. This situation thrust a greater workload on him and might in part also account for his rapid rise in the service. Horsfall claims to have been embedded with the federal troops in
Opobo,
Calabar,
Onne, and
Port Harcourt; he obviously would have held some advantage in this role because he was indigenous to the area. In 1972, Horsfall married Henrietta. She was one of a couple of young women he had helped move to
Lagos to continue their education during the civil war, and he knew her family. They have seven children. ==National Security==