Until the mid-1970s, when a major restructuring of the nation's police system was undertaken, the Philippine Constabulary alone was responsible for law enforcement on a national level. Independent city and municipal police forces took charge of maintaining peace and order on a local level, calling on the constabulary for aid when the need arose. The National Police Commission, established in 1966 to improve the professionalism and training of local police, had loose supervisory authority over the police. It was widely accepted, however, that this system had several serious defects. Most noteworthy were jurisdictional limitations, lack of uniformity and coordination, disputes between police forces, and partisan political involvement in police employment, appointments, assignments, and promotions. Local political bosses routinely used police as private armies, protecting their personal interests and intimidating political opponents.

In order to correct such deficiencies, the 1973 constitution provided for the integration of public safety forces. Several presidential decrees were subsequently issued, integrating the police, fire, and jail services in the nation's more than 1,500 cities and municipalities. On August 8, 1975, Presidential Decree 765 officially established the joint command structure of the Philippine Constabulary and Integrated National Police. The constabulary, which had a well-developed nationwide command and staff structure, was given the task of organizing the integration. The chief of the Philippine Constabulary served jointly as the director general of the Integrated National Police. As constabulary commander, he reported through the military chain of command, and as head of the Integrated National Police, he reported directly to the minister (later secretary) of national defense. The National Police Commission was transferred to the Ministry (later Department) of National Defense, retaining its oversight responsibilities but turning over authority for training and other matters to the Philippine Constabulary and Integrated National Police.

The Integrated National Police was assigned responsibility for public safety, protection of lives and property, enforcement of laws, and maintenance of peace and order throughout the nation. To carry out these responsibilities, it was given powers "to prevent crimes, effect the arrest of criminal offenders and provide for their detention and rehabilitation, prevent and control fires, investigate the commission of all crimes and offenses, bring the offenders to justice, and take all necessary steps to ensure public safety." In practice, the Philippine Constabulary retained responsibility for dealing with serious crimes or cases involving jurisdictions far separated from one another, and the Integrated National Police took charge of less serious crimes and local traffic, crime prevention, and public safety.

The Integrated National Police's organization paralleled that of the constabulary. The thirteen Philippine Constabulary regional command headquarters were the nuclei for the Integrated National Police's regional f6d l commands. Likewise, the constabulary's seventy-three provincial commanders, in their capacity as provincial police superintendents, had operational control of Integrated National Police forces in their respective provinces. Provinces were further subdivided into 147 police districts, stations, and substations. The constabulary was responsible for patrolling remote rural areas. In Metro Manila's four cities and thirteen municipalities, the Integrated National Police's Metropolitan Police Force shared the headquarters of the constabulary's Capital Command. The commanding general of the Capital Command was also the director of the Integrated National Police's Metropolitan Police Force and directed the operations of the capital's four police and fire districts.

As of 1985, the Integrated National Police numbered some 60,000 people, a marked increase over the 1980 figure of 51,000. Approximately 10 percent of these staff were fire and prison officials, and the remainder were police. The Philippine National Police Academy provided training for Integrated National Police officer cadets. Established under the Integrated National Police's Training Command in 1978, the academy offered a bachelor of science degree in public safety following a two-year course of study. Admission to the school was highly competitive.

Integrated National Police was the subject of some criticism, and the repeated object of reform. Police were accused of involvement in illegal activities, violent acts and abuse. Charges of corruption were frequent. To correct the Integrated National Police's image problem, the government sponsored programs to identify and punish police offenders, and training designed to raise their standard of appearance, conduct, and performance.

Dramatic changes were planned for the police in 1991. The newly formed Philippine National Police was to be a strictly civilian organization, removed from the armed forces and placed under a new civilian department known as the Department of the Interior and Local Government.

Local police forces were supported at the national level by the National Bureau of Investigation. As an agency of the Department of Justice, the National Bureau of Investigation was authorized to "investigate, on its own initiative and in the public interest, crimes and other offenses against the laws of the Philippines to help whenever officially requested, investigate or detect crimes or other offenses (and) to act as a national clearing house of criminal records and other information." In addition, the bureau maintained a scientific crime laboratory and provided technical assistance on request to the police and constabulary.

Local officials also played a role in law enforcement. By presidential decree, the justice system in the barangays empowered village leaders to handle petty and less serious crimes. The intent of the program was to reinforce the authority of local officials and to reduce the workload on already overtaxed Philippine law enforcement agencies.

Data as of June 1991