Security guard or security officer is a privately-employed person who is employed to protect property and/or people. Usually security guards are uniformed and act to protect property by maintaining a high visibility presence and observing (either directly, through patrols, or by watching alarm systems or video cameras) for signs of crime, fire or disorder; then taking action and/or reporting any incidents to their client, employer and emergency services as appropriate.

Functions and duties

The security guard motto is to "detect, deter, observe and report." Security guards are not normally required to make arrests or otherwise act as police officers except in some United States jurisdictions in which the security officer is invested with arrest powers like those of a county sheriff. In contrast to the above mentioned motto, a Private Security Guard's or Officer's actual primary duty is prevention of crime. Security personnel do enforce company rules and can act (as would any other person) if necessary to protect lives or property. In fact, they frequently have a contractual obligation to provide these actions. Security Officers are often trained to perform arrests, operate emergency equipment, perform first aid, take accurate notes and write effective reports, and perform other tasks as required by the property they are protecting.

One major economic justification for security guards is that insurance companies (particularly fire insurance carriers) will give substantial rate discounts to sites which have a 24-hour presence; for a high risk or high value venue, the discount can often exceed the money being spent on its security program. This is because having a security guard on site increases the odds that any fire will be noticed and reported to the local fire department before a total loss occurs. Also, the presence of security guards (particularly in combination with effective security procedures) tends to diminish "shrinkage," theft, employee misconduct and safety rule violations, property damage, or even sabotage. Many casinos hire security guards to protect the money when transferring it from the casino to the casino's bank.

Security guards also perform access control at building entrances and vehicle gates by ensuring that employees and visitors display proper passes or identification before entering the facility. Security guards are often called upon to respond to minor emergencies (lost persons, lockouts, dead vehicle batteries, etc.) and to assist in serious emergencies by guiding emergency responders to the scene of the incident and documenting what happened on an incident report.

Although security guards are a distinct type of personnel from either police officers or the military, in the United States a very high proportion of security personnel, including most senior management personnel, are either former or retired members of one or both services. Many security guards who don't fit this profile (young people in particular) use the job as a springboard into a police career.

Being a private security guard is by no means a lucrative endeavor. Most first line private security personal are paid a low wage which often does not reflect the risks they endure on duty.