A security officer or security guard is a privately employed worker who guards premises against criminals. Most security guards do not have special powers of arrest or detainment and are often under strict orders to notify law enforcement rather than confront law breakers in a problem situation. However, in certain states (such as South Carolina or Texas), or in environments and events where terrorist attacks are likely, security guards may be granted limited police powers by law enforcement officers, such as the power to arrest.
Security guards can be directly employed by the company whose premises they protect, or can work for specialist security companies who hire out their services. They may also be either licensed by their state to carry a firearm while on duty, or they may patrol unarmed.