In police vernacular, "surveillance" evokes images of cops sitting in cars or near windows for hours or days at a time, peering through binoculars and drinking lots of bad coffee. That kind of surveillance still happens, but it's increasingly common to have 24-hour surveillance of a location by way of cameras or listening devices that may or may not have someone actively viewing the output at the receiving end. Modern wireless networks and new battery technologies make it possible to locate these unmanned stakeouts virtually anywhere and without breaking the bank to do it.

The most common-and one of the most controversial-means of continuous surveillance is with the use of video cameras mounted on utility poles, buildings, and other vantage points where officers can "see" activity on streets and in public places like parks and transit terminals.

4 Million Cameras

Police in the United Kingdom have led this initiative. There are 4 million cameras operating throughout the U.K. and more than 1 million active in London alone. Most of these are actively monitored by police constables (PCs) in central stations. PCs stand watches at control panels where they see the output of many cameras on wall-mounted displays.

There have been some dramatic episodes where the watchers saw crimes occurring in real time and quickly dispatched patrol PCs to the scene. Suspects who would have otherwise walked calmly from the scene and gone undetected were identified by the surveillance crew, who used their radios to direct the beat cops to the guilty party.

Unfortunately, recent reports indicate this kind of bust is the exception, rather than the rule. In August, the BBC reported that the cameras are rarely effective in detecting or solving crimes. Solved cases that involved the use of surveillance camera video in London worked out to one case for every 1,000 cameras in 2008. The British government has spent £500 million ($821 million) on public safety surveillance cameras nationwide, and citizens are demanding greater accountability from their police.

The Chicago Experience

Here in the United States, the Chicago Police Department is a big believer in surveillance cameras. There are more than 2,000 government-operated cameras pointed at Chicago streets, transit stations, housing authority properties, and critical infrastructure installations around the city.

Some 170 of these cameras are "blue light cameras," marked with flashing blue lights and Chicago PD emblems identifying them as police cameras. Most of the cameras are mounted on utility poles. They reside in bulletproof, weatherproof housings and can be panned and zoomed by operators in the department's communications center, in district stations, and in some cases by officers in patrol cars.

CPD literature calls the camera a Police Observation Device (POD). And the department's experience has been very different from that in the U.K. A total of 30 PODs were deployed in early 2003 as a pilot program called "Operation Disruption." The idea was to proactively intervene on crime in the areas where the PODs were used. The results were highly positive. All calls for service decreased by 44 percent, with calls related to narcotics down 76 percent in the monitored neighborhoods. At the same time, narcotics arrests in the beats adjoining the target areas increased by almost 152 percent, indicating that dealers and users were migrating away from the cameras.

By December 2003, CPD increased the POD deployment to 80 cameras, and added equipment so that all cameras could transmit wirelessly. The PODs were intended to be relocated as needed, and they were moved frequently to meet changing crime profiles and cover blind spot areas. In 2005, the department added to the inventory "hybrid" PODs that were less prominent. These devices still had flashing blue lights, but they didn't operate continuously. Operators could start the lights flashing from the control center at any time. The next year brought the addition of "Micro-PODs" containing two cameras: one mounted on a rooftop and the other on a tower for high-elevation shots.

In 2006, the Illinois Board of Education recognized that students were at highest risk of violence at the end of the school day. This is when assaults took place near school grounds or at parks, transit stops, and other high-traffic areas. By the end of the 2007 school year, 103 PODs were installed in these areas, and patrols were increased when students were leaving school.

There are many success stories where the surveillance cameras were instrumental in solving street crime incidents, aided in monitoring plainclothes officers engaged in stings and decoy operations, and addressed quality of life issues such as panhandling, public drunkenness, and vandalism.

Unfortunately, there are also unintended consequences and liabilities. In September, a surveillance camera recorded an off-duty Chicago officer allegedly beating a Chicago Transit Authority bus driver unconscious. The officer claimed the driver cut him off as the officer was riding his bicycle in traffic. And when the mortal assault of a Chicago teenager was recorded by a cell phone camera and later broadcast on CNN, the blue light camera at that location wasn't working, despite having been reported inoperative three weeks previous. With police surveillance cameras, it's clear the Skylab Rule applies: if you can't keep it up, don't do it.

[PAGEBREAK]Resolution and Bandwidth

The technology of the cameras themselves has been driven largely by the demand in the consumer market for higher resolutions and more light sensitivity for still and video cameras. Public safety reaps the benefit without a large investment in research and development because virtually every feature available on a surveillance camera can be had on consumer products available at Best Buy.

Standard closed-circuit television (CCTV) cameras don't produce video that is anything to get excited about. A color CCTV camera typically maxes out at 560 lines of resolution, or a little better than standard broadcast video (480 lines). Internet protocol (IP) based video cameras produce up to five megapixels of resolution, more information than you can see on an HD television display. But the high-resolution IP cameras are very expensive, and their output takes up a lot of bandwidth. For this reason, most surveillance cameras are CCTV.

In the movies, the good guy can tell a technician to "zoom and enhance" an area on a fuzzy surveillance video, and he'll get a clear shot of a license plate, the label of a package lying on the front seat of a car, or a portrait of the killer reflected in the chrome of a hubcap mounted on a car moving in the opposite direction at 60 mph. In reality, there are several limiting factors affecting the kind of images you can expect.

High-resolution images are available (if you can afford the hardware), but there's still the problem of bandwidth. Unless you just happen to have access to a fiber-optic network on the utility pole where your camera resides, you're probably going to have to rely on wireless data.

The most common wireless networks are variations of the Wi-Fi technology available on every laptop computer and at most coffee shops these days. How much data can be pumped through that connection is a function of the bandwidth of the hardwired node you're connecting to, how many other users are sharing that connection, and what they're sending or receiving. It's not much different than sharing water from a single pipeline. You're never going to get more than the capacity of that pipeline and most of the time you'll get a lot less.

Earlier this year, the FCC allocated the 4.9GHz frequency band exclusively for public safety use. This means that first-responder agencies do not have to share wireless data bandwidth with consumers and private sector users, providing they have the proper equipment and a license. The 4.9GHz frequency band can support, in theory, 54Mbps (a typical cable internet connection is around 5Mbps), so there's more capacity for the agencies that can buy the equipment and not saturate the band.

Depth of Field

Other factors that affect the images include focus and depth of field. When there's lots of light, cameras use small apertures (measured in f-stops like f5.6) and the zone where everything is in focus is larger. This in-focus zone is called the depth of field.

As light decreases, the camera has to open the aperture wider, and the depth of field decreases. Photo manipulation can resolve many problems with an image, but bad focus is very hard to correct. Any agency that is going to depend on a lot of video-based evidence to solve cases is well-advised to obtain a forensic video setup and train some officers in its use. A typical forensic video "lab" (consisting mostly of a powerful desktop computer and appropriate software) costs around $30,000, but can work miracles in the hands of a skilled technician.

Surveillance cameras can act as force multipliers, but the effectiveness of the cameras can also be multiplied by piggybacking them with audio surveillance systems that triangulate and pinpoint the location of gunshots in real time, and automated license plate recognition (ALPR) systems that passively record the license plates of every vehicle that passes within their view.

Citizen Concerns

For every citizen who praises and welcomes public safety surveillance systems, there seems to be at least one more who condemns the technology as an invasion of privacy.

George Orwell's novel "1984" predicted a totalitarian society where every public venue and virtually every room in private residences was dominated by a "telescreen" that constantly broadcast propaganda extolling "Big Brother" and vilifying whatever nation was opposing him.

The telescreen had a feature not found in real-world TVs-while you watched it, it watched you. Any behavior that appeared suspicious or subversive invited a rebuke from the person on the display or a visit from the universally feared Thought Police.

So long as police cameras aren't peering into windows or other areas where there is a reasonable expectation of privacy, organizations like the American Civil Liberties Union and the Electronic Privacy Information Center don't have a valid cause of action to prohibit them.

Still, Chicago and other cities have proposed laws requiring certain crime-prone businesses to install security cameras. Will these cameras eventually feed into public safety monitoring centers, and could someone raise a valid privacy concern because of it?

It's too soon to tell. Surveillance technologies are changing the street crime world, and maybe the legal world, too.

Tim Dees is a retired police officer and the former editor of two major law enforcement Websites. He can be reached at editor@policemag.com .

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