Do surveillance systems reduce crime?
- By Kevin McCaney
- Sep 20, 2011
Do surveillance cameras prevent crime?
Cities around the country have been installing camera systems in recent years, often funded by federal Homeland Security grants, and many have reported good results, but independent research on their effectiveness has been scarce, according to the Urban Institute.
So the institute, which does economic and social policy research, studied the surveillance systems in three cities — Baltimore, Chicago and Washington, D.C. — and recently issued a report on how they affected crime rates.
Under surveillance: Cities struggle to balance safety, privacy
The verdict: The presence of cameras was effective in reducing crime for some, though not all, areas. The key isn’t in just having cameras, the report states, but in how they’re used — how many cameras are employed and where they’re set up, how well they’re monitored, and how well officials balance privacy concerns with utility.
In Baltimore, officials installed 500 cameras mostly in a 50-block downtown area, monitored by retired police officers in a control room, and saw crime rates drop steadily. In other neighborhoods, though, the results were mixed, the report states, dropping in some areas but not in others.
Chicago flooded its downtown with 6,000 cameras, paid for by a combination of federal, state and city funds. The institute’s study focused on two neighborhoods, Humboldt Park and West Garfield Park, that had a combined 2,000 cameras.
It found that crime rates dropped in one area but not the other. The report attributes the discrepancy to the fact that Humboldt Park, where crime decreased, had a higher concentration of cameras, and that West Garfield Park residents thought police weren’t consistently monitoring the cameras.
Monitoring may have come into play in Washington, where cameras didn’t have an impact on crime rates, the report states. After the District installed cameras in high-crime areas, residents raised privacy concerns, leading officials to restrict monitoring. The cameras can be monitored only from a control room where a police official with the rank of lieutenant or higher is present, an officer typically is watching feeds from four or five cameras at a time, and police are prohibited from monitoring people based on race, gender, sexual orientation and other factors.
Mixed results notwithstanding, the report concludes that the cameras are an effective tool in reducing crime if deployed the right way, and they can be worth the sometimes substantial investment in setting up the systems.
In Chicago, for instance, where crime dropped in one area but not in another, the institute’s report determined that the city still saved $815,000 a month on “criminal justice costs and victims’ financial and emotional costs,” and that, “the crimes prevented in Humboldt Park saved the city $4.30 for every dollar spent on the surveillance system.”
The report offers recommendations for helping to improve the chances of success with surveillance systems, including:
Balance utility with privacy. Residents must be protected from invasions of privacy, but rules that are too strict can limit the systems’ effectiveness. In the areas in the study where crime rates didn’t drop, police might not had had enough cameras and might not have been actively monitoring them.
Involve the community. Explaining the reasons for a surveillance system and getting community input from the start can help gain acceptance.
Don’t underestimate costs. In all three cities, the costs of installing, maintaining and monitoring the systems was higher than officials originally thought.
Start small, and place cameras carefully. Beginning with a couple cameras lets police figure out how to best use them, before expanding the program.
Invest in active monitoring. Although 24-hour, active monitoring raises privacy concerns, Baltimore police said it gave them the best results, sometimes allowing officers to get to a crime in progress.
Train detectives and prosecutors. Video evidence not only helps police investigate crimes, it can be used as evidence in court. But it has its limits, particularly if a crime was recorded in bad weather or at night, or if the camera did not catch all of a crime because it was not being monitored. When monitoring, police can direct the camera, otherwise, it pans across an area. Baltimore prosecutors reported running into the “CSI effect,” in which juries expect high-quality forensics and technical evidence, and might be influenced if video evidence shows only part of a crime because the camera panned away. The report recommends prosecutors be trained in the best ways to present surveillance footage as evidence.