What Is CCTV?

Closed-circuit television (CCTV) is a security monitoring system of one or more video cameras that transmit a signal to a specific set of monitors. The signal can travel over point-to-point (P2P), point-to-multipoint, or mesh wireless links. Banks, casinos, airports, shopping malls, military installations, and convenience stores all use CCTV to deter crime — and it serves other roles too, from watching an industrial plant’s control room to broadcasting distance-education courses. Modern systems add digital video recorders (DVRs), email alerting, megapixel sensors, and recording to network-attached storage, and they’re used worldwide, especially across industrialized nations.

History

In 1942, the first CCTV system was installed by Siemens AG strictly to observe the launch of V-2 rockets; it was designed by German engineer Walter Bruch. In 1949, the United States released Vericon, the first CCTV system that didn’t require a government permit to own and operate — and such systems are still used to monitor launch sites for malfunctions. In 1973, the New York Police Department installed the first CCTV camera in Times Square to deter crime, though it reportedly had little effect at first. Through the 1980s, video surveillance spread across the U.S. in high-traffic areas as a cost-effective alternative to expanding police forces, and businesses adopted it to monitor shoplifting. In the 1990s, digital multiplexing let a series of cameras record simultaneously with time-lapse and motion-only options, and departments installed cameras in schools, parks, housing, social venues, and sporting events. After the September 11 attacks, CCTV became commonplace in the U.S. as a counter-terrorism tool.

Uses

Research by criminologists Brandon Welsh (Northeastern University) and David Farrington (University of Cambridge) found CCTV most effective in parking lots, public-transport areas, and other public settings, with notably higher success in countries like the United Kingdom. Overall success depends on a mix of factors — for example, the strong results in parking lots may reflect a higher camera density than in transit areas. CCTV aids the detection and conviction of offenders by tracing the movements of suspects or victims, has been used to track suspects since the 1970s, and is deployed on transit vehicles and in mobile police surveillance vans. Beyond that, applications vary with each organization’s needs.

CCTV & Privacy

Critics argue that surveillance technology infringes on the right to privacy and chips away at civil liberties — and that CCTV simply pushes criminals to change tactics. They often invoke “Big Brother,” the surveillance society of George Orwell’s 1984. Proponents counter that cameras only record public space and so don’t violate privacy; critics point to the U.S. Supreme Court’s Katz v. United States, which recognized a reasonable expectation of privacy. Activists have also raised concerns about unauthorized access to recordings. In the United Kingdom, legislation has sought to restrict CCTV use and require registration with data-protection authorities. As the technology grows — adding real-time video content analysis (VCA) and facial recognition — so does public scrutiny.

Technology Developments

High-definition CCTV cameras run computer-controlled processes such as video content analysis, which detects events rather than relying on a single still image. A VCA-equipped system can recognize, identify, and compare objects in a database by size, speed, and color — its response depends on what the equipment “sees.” A programmed alarm might sound if an object moves from a set spot, and the system can flag unusual patterns: if someone moves against the normal flow of traffic in an airport, an operator can zoom in to watch for suspicious behavior. VCA can also estimate a person’s position from still images, link a series of cameras, and follow an individual across a large area without analyzing every move.

A facial recognition system automatically identifies or verifies a person from a digital image or video frame by comparing facial features against a database. Combined with CCTV, it has been used for mass surveillance, though many operators have backed away because of high false-positive rates. Even so, proponents advocate its use at air and seaports for screening. The broader trend is toward computerized monitoring that reduces the need for a human operator, enabled by Internet Protocol (IP) cameras that transmit video digitally across data networks.

CCTV Resources & Research

Authoritative, current sources on CCTV effectiveness, law, and privacy.

Frequently Asked Questions

Common questions about CCTV and video surveillance.