Do Surveillance Cameras Reduce Crime?

Many cities, businesses, and individuals have installedWe have all seen the news reports about the 2005
Closed-Circuit TV (CCTV) cameras for surveillanceLondon Terrorist bombings of the subways. Without
purposes. London in particular, has installed thousandsthe camera systems, where officials were able to
of surveillance video cameras. New York City withtrack the movements of the perpetrators, it is very
more than 4000 video cameras in just Manhattan, haslikely that it would have taken much longer to solve
adopted many of the same strategies as London, andthose crimes.
cities across the U.S. are on a comparable path. TheseSurveillance works best when there is a system
cameras make many people feel safer, but thisobserving the camera output. But human time is
technology can make other people concerned with aexpensive, and this is where video analytics can be
perceived loss of privacy.important. If a computer can screen many cameras,
The investment required for a surveillance camera canand have the human review only the probable events,
be significant. Some of these cameras can cost up tothen a single human can monitor many more cameras.
$60,000 each, and that is before the cost for humanIt is also more rewarding for the human not to watch
resources to monitor the output is considered. J.P.camera output from eventless images. But we should
Freeman, a security market analyst company, projectskeep our expectations realistic.
that the U.S. will annually invest 21 billion dollars in theseIf we believed Hollywood, camera systems with this
systems by 2010. The market for CCTV systems inkind of artificial intelligence have almost mystical power.
the U.S. increased by almost 700 percent from 1980 toThe truth is that it is very difficult for a computer to
2000.interpret many environments, at least with today's level
Do the experiences to date, show that surveillanceof technology. However, a computer system equipped
cameras improve the public's safety? Because of thewith video analytics software, teamed with a skilled
political agendas in play, with the camera industryhuman, can effectively monitor many cameras.
biased in favor and civil libertarian groups biasedChicago has hired IBM to install camera systems with
against, the answer is clouded with hyperbole.video analytic software. "That's really going to just
For example, the headline from a news article about athrow our camera network into hyperdrive," said Kevin
study conducted by the University of California "CenterSmith, a spokesman with the Chicago's Office of
for Information Technology Research in the Interest ofEmergency Management and Communications
Society" (CITRIS) read "SF SURVEILLANCE(OEMC). "Ultimately I think what this software might be
CAMERAS DON'T STOP VIOLENT CRIME".able to do is simply recognize suspicious behavior and
However, this CITRIS study found that the camerasalert our operations people and, at times, our crime
were very effective in reducing property crimes withindetections specialists as to what it sees." Chicago is
100 feet of the cameras, resulting in a reduction of 24installing surveillance cameras on all of their buses and
percent, but that fact was buried in the news article.subways to provide mobile eyes on the city. Once
The CITRUS study was very thorough and istheir mobile broadband system is in place, the data will
frequently cited as evidence that surveillance camerasbe available in near real-time. Chicago is the world
don't work, even though the study found significantleader in the application of video analytics on this scale.
positive effects from the cameras. However, becauseSurveillance cameras can be a deterrent to crime. In a
those results may not be consistent with the agenda,study of convenience stores, CCTV surveillance
those results are often not reported.showed impressive results. A sample of 81 stores
There is also bias from industry groups, since theywere studied for 1 year before and and 1 year after
make their money from selling cameras. The newestthe installation of CCTV camera surveillance systems.
technology in camera surveillance is the use ofThe rate of robbery decreased by 53 percent after
computers to interpret the data. This is a kind ofthe cameras were installed. The New York City
artificial intelligence that is called "video analytics", and isHousing Authority estimates that the CCTV systems
potentially beneficial for efficient use of surveillancehave reduced crime by 36% in their public housing.
cameras, but this technology has sometimes beenBaltimore (17%), Dallas (11%) and Philadelphia (37%)
significantly oversold by the surveillance cameraalso report improvement in the rate of crime because
industry. This technology works best in less complexof their downtown camera monitoring systems.
environments, such as a warehouse or loading dockHowever, not every city reports improvement.
that should be idle. Video analytics works much lessWashington D.C., for example, says that their cameras
well in busy environments like a crowd at a shoppinghave proven ineffective. In a British study, of 14 British
mall.cities that utilized a CCTV system, the systems had
"Some of the claims that are made are just ridiculous,"little effect on crime in six of the cities.
says Oliver Vellacott, CEO of IndigoVision, a BritishThe conclusion is that a successful camera
company that develops video analytics technology. "It'ssurveillance program requires more than just installing
important not to believe all the ridiculous hype andhardware. An effective program comprehends that a
nonsense about what analytics can deliver."camera that is not monitored, is a dumb piece of
It has been demonstrated many times that camerahardware, and the camera system will lack credibility.
recording can be used to solve crimes. The ChicagoDallas uses retired and light-duty officers for their
Police Department estimates that the web of camerascamera monitors. Smart systems (video analytics) can
installed in their city has been an important tool, resultingmake human monitoring much more efficient. Over
in more than 1,200 arrests since 2006. The Dallastime, as camera systems successfully address crime,
Police Department has reported more than 1,700the deterrence effect of the cameras will improve.
arrests in a similar period from their camera system.This is the message from London and New York.