A Brief History

Regulation of the private security industry began in 1915, when California enacted a licensing requirement for private investigators. The history of the industry in the United States, however, dates back nearly another century. One of its founders was Allan Pinkerton, who immigrated to this country in 1843. By 1850, he had founded the Chicago-based Pinkerton National Detective Agency, which would quickly become the industry's largest private security companies. Among the Agency's main customers were the railroads, which had to contend with outlaws who robbed trains of cargo and passengers of personal possessions. In the mid-1800s, there were no federal authorities to chase outlaws across state and territorial lines, and local law enforcement was too poorly equipped to pursue fleeing gangs very far. Therefore, the job fell to crime victims and their hired agents. The Pinkerton Agency's work for the railroads helped build an international reputation for the company.

In addition to tracking down and apprehending criminals, the early private security industry performed many other duties now associated with federal and state law enforcement: guarding interstate railroad and stagecoach shipments , investigating crimes and providing security advice to banks and other businesses that were frequent targets of outlaws. Much of this work diminished when federal and local agencies improved their law enforcement capabilities shortly after the turn of the 20th century. However, the industry had grown considerably by that time, with large numbers of people working as private guards, detectives and other security-related jobs, many of them armed. That growth was part of the reason that regulation became necessary.


  • 1915: California moves to license and regulate private detectives under the Administration of the State Board of Prison Directors.
  • 1943: A new category for Private Patrol Operators is added to the Private Investigator Act.
  • 1949: Repossessor agencies are added to the licensing categories under the Collection Agency Act
  • 1950: The Detective Licensing Act is renamed the Private Investigators and Adjuster Act.
  • 1959: Repossessor agencies, formerly regulated under the Collection Agency Act, are transferred to the Private Investigator Act
  • 1973: The Bureau of Collections and Investigative Services is mandated to register uniformed employees of Private Patrol Operators.
  • 1974: The firearm program is established, requiring applicants for exposed weapon permits to complete Bureau-approved training.
  • 1977: Alarm companies and agents are required to be licensed.
  • 1981: Repossession employees are required to be licensed.
  • 1986: Locksmiths are required to be registered.
  • 1993: The Locksmith Act is expanded to require separate licenses for locksmith companies and their employees.