Private security and public police provide some of the same services and sometimes they even mirror each other, but there are distinct differences among the similarities. The scopes of their duties are different and each has advantages and disadvantages
Allen Pinkerton established the first private police organization (Northwest Police Organization) in 1855, By the end of the century, other organizations like Burns and Wackenhut were also established. Contact security guards were used heavily by industrial companies in the early part of the 20th century and were used as strikebreakers. In 1930, The Ford Motor Company had a private police force of 3,500 called "The Ford Service."
Private security is contracted services to companies, people or organizations for the protection of personnel and property. Private security includes guard services, private investigators, body guards and retail (in-house) detectives. All of these positions have limited police powers, and need some training and licensing, but have fewer restraints than public police.
America's law enforcement roots can be traced back to English police models that were used from colonial times up until 1800's. In the 1800s America experienced economic and social changes--industrialization, urbanization and immigration that forced changes in law enforcement making not just a local responsibility, but also a county, state and federal responsibility. This brought about the forming of police departments and jurisdictions, with New York being the first city to establish a police force in 1844. Other social changes again forced changes in law enforcement--1960s, civil rights and the 1980s drug trafficking.
Public police are part of a government entity--local, county, state or federal. All public police are based on a paramilitary model and have strict requirements, training and certification.
Public police are controlled by politics and government establishments, and restrained by laws and rules, but their role is the safety and welfare of the public.
Private security and public police have their advantages and disadvantages. Private security companies have less restrictions placed upon them, thus they can focus and effectively carry out their contracted duties.
Private security also gets paid by performance and can negotiate salary. Also, private security has more technical equipment available to them--depending on the employer).
The main disadvantages of private security personnel is lack of training or updated training and job retention, since they are contracted and based on performance they are more easily subjected to termination.
Public police face a number of disadvantages, since they are salary employees they have less negotiation powers and they do not get extra compensation for exceptional performance. Police also are hampered by restrictions, legal and political; they are understaffed and not accessible to newer technology due to budget restraints and hiring limits. Police do have advantages in training/advance training and in job retention.