The potential value of public surveillance technology took on new meaning last week when investigators identified the two suspects in the Boston Marathon bombing after sifting through video images captured by the city’s cameras.
This has prompted public officials like Chicago Mayor Rahm Emanuel to speak of the “important function” such cameras play in offering safety on a daily basis and during events both big and small.
The successful use of this technology in such a high-profile investigation is likely to prompt other major cities to reaffirm – and even expand – their investment in and use of surveillance cameras. Civil liberties advocates fear this would create an undue invasion of privacy.
In the ensuing debates over privacy versus safety, advocates on both sides would be wise to consider the following guidelines.
Public surveillance cameras and civil liberties can coexist if cameras are implemented and employed responsibly. Our guidebook for using public surveillance systems advises law enforcement to consider privacy issues when creating surveillance policies. For one, cameras should avoid or mask inappropriate views of private areas, such as yards and second-story windows. Law enforcement agencies should also document and publicize policies governing how surveillance cameras can be used and what the disciplinary consequences are for misuse. Likewise, officers should be thoroughly trained on these policies and held accountable for abiding by them.
Public surveillance camera systems can be a cost-effective way to deter, document, and reduce crime. Urban’s research has shown that in Baltimore and Chicago, cameras were linked to reduced crime, even beyond the areas with camera coverage. The cost savings associated with crimes averted through camera systems in Chicago saved the city over four dollars for every dollar spent on the technology, while Baltimore yielded a 50 cent return on the dollar.
The usefulness of surveillance technology in preventing and solving crimes depends on the resources put into it. Our evaluation of three cities found that the most effective systems are monitored by trained staff, have enough cameras to detect crimes in progress, and integrate the technology into all manner of law enforcement activities.
As with any technology, the use of cameras is by no means a substitute for good old-fashioned police work. The detectives we interviewed reported that camera footage provides additional leads in an investigation and aids in securing witness cooperation. And prosecutors noted that video footage serves as a complement to—but not a replacement for—eyewitness evidence in the courtroom.
Technological advances will continue to enhance our ability to monitor public spaces. By extension, technology will continue to aid efforts to prevent crime and apprehend criminals. While the use of cameras to identify suspects involved in the Boston Marathon bombings may prompt cities to seize upon additional surveillance opportunities, they should do so cautiously—and with the benefit of lessons learned from other cities.