The RTP employs between , and , officers, roughly 17 percent of all civil servants excluding the military and the employees of state-owned enterprises.
Officers also undergo paramilitary training similar to the army but with an additional focus on law enforcement. Until the 19th century Royal Thai Armed Forces personnel, aside from their duties of national defence, also performed law enforcement duties alongside dedicated civil servants. Responsibility for law and order was divided into the six ministries led by chancellors of state during the Ayutthaya and Thonburi eras ; in time of war, police units were under royal command as part of the army.
Only during the reigns of King Mongkut Rama IV and King Chulalongkorn Rama V did the nation see a huge reform and the Westernization of Thai law enforcement forces to adapt to the changing situation and needs of the country. In the provincial and urban police forces were united as one national organization under the Ministry of Interior established Primary responsibility for the maintenance of public order through enforcement of the kingdom's laws was exercised by the Thailand National Police Department TNPD , a subdivision of the Interior Ministry.
Charged with performing police functions throughout the entire country, the TNPD was a unitary agency whose power and influence in Thai national life had at times rivalled that of the armed forces itself. The formal functions of the TNPD included more than the enforcement of laws and apprehension of offenders. The department also played an important role in the government's efforts to suppress the remnants of the communist insurgency.
In the event of an invasion by external forces, much of the police force would come under the control of the Ministry of Defense to serve with, but not be incorporated into, the military forces. Originally modelled on the preβWorld War II national police force of Japan , the TNPD was reorganized several times to meet changing public order and internal security needs. American advice, training, and equipment, which were provided from through the early s, did much to introduce new law enforcement concepts and practices and to aid in the modernization of the TNPD.
