Ordinance #25, approved on May 14, 1852, established a Department of Police with the Mayor as its chief executive. The Mayor was to prepare rules and regulations for the department, subject to the approval of the Common Council. Legal voters who could read and understand English were eligible for membership on the force. A chief of police was responsible to the Mayor for the efficiency, general conduct, and good order of the department. He kept a record of all police business and of all free persons of color in the city (independent of the registers kept by the Mayor). The captains of each municipal district were also to keep such books as required by the Mayor and chief.

Ordinance #2100 of 1855 required that prospective police officers had to be recommended to the Mayor by at least three freeholders of New Orleans and also had to have been two years resident in the city and a citizen of the United States. Those officers who were to serve in the districts below Canal Street had to be able to speak French as well as English. All officers were further required to give bond and security to the Mayor for the faithful performance of their duties. This ordinance also set the size of the force at 265, including 250 policemen, ten sergeants, four lieutenants, and one captain. Later ordinances increased the numbers of the force and apparently also made the captain the chief of police and the lieutenants, captains. Other laws called for the assignment of special officers to serve in the following capacities: syndic for the rural portion of the Third District; special policeman for the Milneburg resort on Lake Pontchartrain (also in the Third District); and as superintendent of the horse market in the First District.

The duties and responsibilities of the police were expressed in both general and specific terms.More general provisions made the police, along with other public officers, responsible for enforcing local ordinances against a variety of offenses and nuisances. Among their specific duties were to:

• inspect bread baked and offered for sale in the city
• report illegal awnings and sheds over the sidewalks
• enforce orders issued by the Board of Health
• arrest persons playing music in any establishment where liquors were sold, to order the closing of such businesses in time of riot or other public disturbance, to arrest enslaved people drinking or playing cards in cabarets or on the street, and to arrest white and persons of color drinking or playing cards together
• fire the evening guns in the first district
• ring the fire bells in case of fires and to keep onlookers away from fire fighters
• arrest "lewd women" frequenting coffee houses, cabarets, and such establishments
• enforce the laws relative to the slaughterhouses by weekly visits to each
• arrest enslaved persons living away from their enslavers and to enforce other laws passed for the control of enslaved persons

Following the Civil War and the suspension of civil government in New Orleans the department was reorganized by ordinance #16 in 1866. Under this legislation the force numbered 500 policemen along with a chief, four aids, and four lieutenants. The chief was entrusted with the general supervision and control of the department, subject to the Mayor's approval. The Mayor retained responsibility for preparing the rules and regulations for the force. A Police Commission, created by state act in the same year, was to act as a tribunal to hear charges brought against policemen and to suspend or dismiss those found guilty. The qualifications of police officers basically remained the same, except that citizenship of at least five years duration was now required. Subsequent legislation authorized the Mayor to appoint officers to serve as river police, to patrol the City Park, and to staff a police station near the barracks. The commissaries of the various markets were required to wear police badges. All of these men were subject to the control of the chief of police.

This force exercised the police power in New Orleans until the passage of the Metropolitan Police acts of 1868/1869 and the March 5, 1869 act that specifically prohibited the Mayor from wielding any police authority in the city. The city charter of 1870 did provide for a department of police, provided that it have no power in conflict with the Metropolitan Police. Following the dismantling of the Metropolitan force in 1877, ordinance #3889 of that year reconstituted the local department as the Crescent City Police under the control of the Mayor and an Administrator of Police. Ordinance #3914 later detailed the duties and responsibilities of the police, but the departmental organization was essentially the same as it had been in 1866.

This department remained in place until 1889 when a new force was organized along the principles of act #63 of 1888. For the first time police officers were required to have physical and moral qualifications. That essentially marked the beginning of the modern New Orleans Police Department.