Security guards do this by maintaining a high-visibility presence to deter illegal and inappropriate actions, looking (either directly through patrols, or indirectly by monitoring alarm systems or video surveillance cameras) for signs of crime or other hazards (such as a fire), taking action to minimize damage (such as warning and escorting trespassers off property), and reporting any incidents to their clients and emergency services (such as the police or emergency medical services), as appropriate.

Security personnel may also perform access control at building entrances and vehicle gates; meaning, they ensure that employees and visitors display proper passes or identification before entering the facility.

Security officers are called upon to respond to potential hazards (such as broken lights or doors, disturbances, lost persons, minor injuries, etc.)

Armed security officers are frequently contracted to respond as law enforcement until a given situation at a client location is under control and/or public authorities arrive on the scene.

Until recently the most commonly used form used to be mechanical clock systems that required a key for manual punching of a number to a strip of paper inside with the time pre-printed on it.

[citation needed] On the other hand, some security officers, young people, in particular, use the job as a practical experience to use in applying to law enforcement agencies.

[13] Specialized VIP security guard services and companies are in high demand and are defined by their ability to protect celebrities and executives during times of unrest.

[18] The review referenced a 2007 report from IBISworld (2007:24) that indicated four out of five of the largest private security companies in Australia were foreign-owned, accounting for 44.5% of the market share at the time.

[18] A 2018 report authored by Anthony Bergin, Donald Williams, and Christopher Dixon and published by the Australian Strategic Policy Institute, focused on the current role of private security in countering hostile threats.

An evolving understanding of threats has resulted in private security playing a greater part in responding to critical incidents, such as terrorist attacks.

It said the security industry is nationally characterized as high-volume and high-turnover, given the conflict between a highly prescriptive selection process by employers and regulators who seek to ensure only fit and proper people are licensed.

In 2018, referencing data provided by ASIAL, the report states that the private security industry has an annual turnover of AUD8 billion – split evenly between manpower and the electronics sector.

Technological advancements in regards to drones, facial recognition, and robotics are expected to continue to augment the private security landscape in Australia.

Most provinces in Canada regulate the use of handcuffs and weapons (such as firearms and batons) by contract security companies and their employees, either banning such use completely or permitting it only under certain circumstances.

There are two different types of vektere—the normal uniformed or civil-clothing officers who watch over private and semi-public properties, and government-hired vektere who work in public places, such as the Parliament.

Security officers may issue fixed penalty tickets for violation of parking regulations in designated areas and for passengers on public transportation without a valid pass.

Licenses are valid for three years and require the holders to undergo formal training, and are also to pass mandatory Criminal Records Bureau checks.

Many locations with a high number of visitors, such as the Jerusalem Central Bus Station, employ X-ray machines to check passenger's bags; in other places, they are opened and visually inspected.

Armed security personnel are generally employed to protect sensitive sites such as government and military installations, armored money transports, casinos, banks and other financial institutions, and nuclear power plants.

The use of private police has particular appeal because property or business owners can directly contract for public safety services, thereby providing welcome relief for municipal budgets.

Applicants must be at least 18 years old, undergo a criminal history background check through the California Department of Justice (DOJ) and the Federal Bureau of Investigation (FBI), and complete a 40-hour course of required training.

To be licensed as an unarmed officer an individual must be at least 18 years of age and undergo 40 hours of classroom training and pass criminal history checks.

Certification involves completing a medical physical exam, a psychological examination, classroom training and qualifying on a pistol range, with firing of 50 rounds of ammo larger than a .380acp.

Certified armed security officers are authorized under state code to arrest[70] for any offense committed in their presence while they are on duty at the location they are hired to protect.

Virginia also allows security officers to attend additional 40 hours of training to become certified as Conservators of the Peace (Special Police) for the company employing them.

Some jurisdictions do commission or deputize security officers and give them limited additional powers, particularly when employed in protecting public property such as mass transit stations.

Other local and state governments occasionally enter into special contracts with security agencies to provide patrol services in public areas.

In 1976, the Law Enforcement Assistance Administration's National Advisory Commission on Criminal Justice Standards and Goals reported: One massive resource, filled with significant numbers of personnel, armed with a wide array of technology, and directed by professionals who have spent their entire adult lifetimes learning how to prevent and reduce crime, has not been tapped by governments in the fight against criminality.

This has resulted in longer guard instruction hours, extra training in terrorism tactics and increased laws governing private security companies in some states.

The vigiles were soldiers assigned to guard the city of Rome, often credited as the origin of both security personnel and police, although their principal duty was as a fire brigade.