One day this past March, Ivy Wilson Terrell came home to find a blinking red police camera installed on a utility pole outside her New Orleans home. The police were launching a citywide surveillance system. “I thought, ‘You have got to be kidding me. This cannot be in front of my house,’” Terrell told The Times-Picayune.

Terrell’s experience is far from unique. Cities nationwide are installing flashing police cameras in an effort to deter crime in certain neighborhoods. While some residents welcome the cameras, others say they feel like they’re being spied on, like they’re living in an Orwellian police state. And to some visitors and businesses, the cameras give the impression that an area is unsafe. That was certainly my notion of these cameras when I first encountered them in Baltimore. The flashing blue lights of the city’s police surveillance cameras made me feel like I’d been transported into an episode of “The Wire.”

But these cameras’ forbidding look deflects from the fact that they serve a purpose. Flashing camera systems have become common policy this past decade, with systems in several U.S. cities and spreading, says Nancy La Vigne, vice president of justice policy at the Urban Institute. Generally placed in crime hot spots, their purpose is twofold: the flash is meant to notify criminals that cameras are in the area and that the footage is being fed to police control rooms. A 2011 Urban Institute study found that these cameras were cost-effective at reducing crime in Baltimore and Chicago.

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La Vigne, who co-wrote the study, says political support for cameras depends on how they’re presented to the receiving communities. In January, New Orleans’ top-down, $40 million plan included license plate readers, cameras outside bars and liquor stores, and the flashing ones in residential areas. The plan received little public input, and was subsequently ripped by protestors, media and the ACLU. Mayor Mitch Landrieu suggested scaling it back before he left office in May.

The more successful programs, says La Vigne, are approached democratically. “Project Green Light” in Detroit, for instance, is a partnership between businesses and the police. Stores pay the city between $4,000 and $6,000 to have flashing cameras installed outside. Memphis has a similar program, in which residents can pool money to have SkyCop cameras in their neighborhoods. In 2016, Memphis allocated money to extend these cameras to underserved areas to help residents who want them but cannot afford them.

This voluntary approach is the best upfront path to winning support for overhead cameras, says La Vigne. Once installed, demand for them seems to grow. In the cities La Vigne studied, “the biggest complaint from the residents was, ‘Why aren’t there cameras in my neighborhood?’”

To that end, aesthetics matter. I found that the flashing green lights in Detroit, while not pleasant, were less harsh than Baltimore’s blue lights and New Orleans’ red ones. So maybe the solution is as simple as making the cameras noticeable enough that they deter criminals, but not so obtrusive that they bother law-abiding citizens.

[This article was originally printed in Governing Magazine.]