By Paul Rosenzweig, The George Washington University Law School
Do CCTV cameras help in reducing crime? One might think that the answer would be yes, based on the theory that surveillance cameras would deter potential offenders. That, after all, is the insight of Plato’s Ring of Gyges—the idea that a ring of invisibility would eliminate deterrence and encourage aberrant behavior. However, the evidence is mixed.

CCTVs
If one had to say what the most prevalent form of police surveillance is today, it would be fixed surveillance cameras—closed-circuit TV, known by its acronym CCTV—and their close cousins, license plate readers.
The United Kingdom has nearly 6 million of these closed-circuit TVs scattered around the country—roughly one for every 11 people in the entire nation. That’s an awful lot of cameras. There can be little doubt that these cameras are effective tools, at least for some purposes.
This is especially so for retrospective investigations. When a crime has occurred, the surveillance video that has been taken—and stored—can be pulled up and analyzed. After four Muslim terrorists detonated bombs in London’s Underground, and on a bus, back in July 2005, the suspects were quickly identified from CCTV footage taken at Luton Station, where they had entered the subway system.
This is a transcript from the video series The Surveillance State: Big Data, Freedom, and You. Watch it now, on Wondrium.
CCTV Footage Help Track Culprits
The London attacks also demonstrated another important aspect of the proliferation of CCTVs. Most of the video is maintained by private sector actors rather than by the government. Soon after the four suspected attackers were identified in London, the UK authorities were able to backtrack their movements over the days prior to the attack.

The CCTV video showed, for example, one of the men arguing with a cashier at a gas station and another video seemed to suggest that the bombers had done a dry run through the Underground as a means of reconnaissance, in the days preceding the attack.
This, however wasn’t unique to London. After the tragic bombing at the Boston Marathon in 2013, a key piece of evidence was obtained from a CCTV camera operated by a department store across the street. This camera showed an attacker leaving a black backpack next to a mailbox, in the precise location of the explosion.
Learn more about modern conception of privacy.
How Effective are CCTVs in Deterring Potential Crimes?
However, as far as their ability to deter potential offenders goes, it’s a mixed response. Take London, for example. There, the cameras are so plentiful that they are called a ring of steel around the city center. But many residents question the effectiveness of London’s system. Only one crime was solved for every 1,000 cameras deployed, according to a police report from one recent year. At the same time, CCTV cameras were costing authorities hundreds of millions of dollars a year, according to Big Brother Watch, a civil liberties group.
In the United States, the Urban Institute reviewed the use of CCTV in three cities—Baltimore, Chicago and Washington, DC. Its findings were—well, confusing. In Baltimore, public surveillance cameras installed in the 50-block CitiWatch section, reduced violent crime by 23% between 2003 and 2008. By contrast, in Chicago, where cameras were put into two communities, only one saw a reduction in crime, while there was no visible effect in the other. And Washington, DC, seems to have identified no appreciable change in criminality after cameras were installed, whatsoever.
License Plate Readers and Their Pervasiveness

Apart from CCTV, there is another type of camera extensively used in policing—the license plate readers. These are fixed cameras that have only a single object of interest—tracking vehicles. The technology for this is actually pretty old-school. Optical character readers are used to translate the image or picture of the license plate into a text that can be easily read and stored.
Most of what happens with respect to collecting license plates is unregulated. The privacy interest also arises when the collection becomes pervasive and systematic. And that’s exactly what is happening.
The Wall Street Journal reported that the Justice Department was building a national database to track, in real time, the movement of vehicles around the United States.
Learn more about the “observer effect”.
Questions on Use of License Plate Readers
The license plate reader program is said to have begun innocently enough, with an initial focus on tracking cars along the Southwest border to follow the movements of drugs and drug money. It was housed at the El Paso Intelligence Center in Texas, a law enforcement intelligence center that’s staffed 24 hours a day. But today, the program is national in scope.
And the Department of Homeland Security has its own database. US Customs and Border Patrol personnel collect information on land border traffic, amounting to hundreds of millions of license plates. And New York City itself has long collected the license plate of every car entering or leaving Manhattan. Perhaps that doesn’t concern you. You might be of the “I have nothing to hide” view.
However, Jay Stanley, a senior policy analyst at the American Civil Liberties Union, reminds us:
Any database that collects detailed location information about Americans not suspected of crimes raises very serious privacy concerns … It’s unconscionable that technology with such far-reaching potential would be deployed in secrecy. People might disagree about exactly how we should use such powerful surveillance technologies, but it should be democratically decided, it shouldn’t be done in secret.
Common Questions about CCTV Surveillance
After the bombing at the Boston Marathon in 2013, a key piece of evidence was obtained from a CCTV camera operated by a department store across the street.
In London, the cameras are so plentiful that they are called ‘a ring of steel’ around the city center.
License plate readers are fixed cameras that have only a single object of interest—tracking vehicles. Optical character readers are used to translate the image or picture of the license plate into a text that can be easily read and stored.