Detroit had a problem. Late at night, gas stations were the only businesses with open doors in many neighborhoods—and they were magnets for crime. In the first six months of 2015, about a quarter of violent crimes reported between 10 p.m. and 8 a.m. happened within 500 feet of a gas station, according to the Detroit Police Department.

So it launched Project Green Light, offering round-the-clock video monitoring to city businesses, which pay all related expenses.

“We call what we do virtual patrol,” said Sergeant Michael Woody, the Detroit Police Department’s public information officer. So called real-time crime centers have been adopted by police departments across the country, but Detroit’s stands out because of the buy-in from local merchants. Each business opts into the additional surveillance with an investment of $5-6,000 for stationary high-definition cameras, lighting, software, technology and an ever-present green light that can be seen from some distance away.

Mike’s Fresh Market is among the local businesses that have joined Project Green Light. Its owner, Jamal Abro, decided to enroll one of his two stores after experiencing “some trouble in the parking lot,” like cars being broken into. Though he has security guards, he felt that the extra measures were necessary to ensure the safety of his customers. Abro will have about seven cameras installed around the perimeter along with signs that indicate that the grounds are being monitored. When the installation is complete he estimates the total cost will be between $8-9,000, “But it will be worth it to make my customers feel more safe and comfortable,” he said. He’s also confident that a positive side effect will be attracting more customers to his store thanks to the enhanced security. For Abro, there’s an improved efficacy and immediacy to Project Green Light that gives him a lot of peace of mind.

“If there’s any problem in the parking lot, if I call 911 by the time they get here it’s all over. But the cameras will have recorded what happened and the police can see it,” he said. Another benefit is that patrol cars on routine rounds now stop to check in on the business and sign a logbook that records when they stopped by. Even when the market is closed, it is monitored by police, and Abro can also use his phone to see if there’s anything going on at his store. The ever-present green light also alerts neighbors and passersby that he store is under surveillance. Abro’s employees, he said, are thankful for his investment. “The cashiers are so happy about it and feel safer.” He plans to make his second store a Project Green Light location soon.

Abro’s enthusiasm is easy to understand, and widespread. In addition to gas stations, liquor stores, and other assorted businesses, multiple McDonald’s locations have signed on. These particular owners are community members, engaged in the community. They employ people from the neighborhoods where they are located. “They want to protect the people that they serve,” Woody said.

The upfront investment the program requires, though, may make it easier for deep-pocketed businesses to gain extra attention from the police department, while others can’t. Participants receive priority if a serious incident is in progress at their location. Woody argued that as demand for monitoring increases, falling prices will make it easier for more businesses to participate. “Because we’re working at such a fast pace with all the installers and manufacturers, we’re starting to see a decrease in cost.” At the moment, about 25 merchants are fully set up and another 80 are at different stages in the installation process.

Does requiring these businesses to fund their own cameras in order to participate in the program represent the privatization of public services? Eric Piza, a professor at John Jay College of Criminal Justice who has studied police surveillance using cameras, doesn’t think so. “Businesses pay for security companies all of the time. If a business wants a burglary alarm, for example, nobody says that the police should pay for that. If this is an upgrade that a business thinks is important, I don't necessarily think that means that the police department shouldn't fit it in as well because, to be honest, the police department sounds like they're giving an important service in exchange for that.”

Woody also pointed out that businesses have other options. They can, for example, request a patrol log book through their Neighborhood Police Officers program. Officers on neighborhood patrols routinely check in and leave a note on log sheets, which are maintained by local precincts, and used to study and analyze crime patterns. “The log book usually addresses small crimes because once people see that officers are coming by a business multiple times a day, they stop whatever they were doing,” Woody said. But if log books were actually as effective as high-definition video monitoring, the program, presumably, would not be as necessary.

In fact, the increased attention that Project Green Light brings to neighborhoods may sometimes prove something of a mixed blessing. Piza acknowledged the risk that the enhanced monitoring might lead to over-policing in disadvantaged areas. “I think it's important for police departments to constantly monitor how they're using the technology, and also constantly monitor not just the outcomes.”

Nor is that the only potential drawback. The cameras are on 24 hours a day, 7 days a week, even when businesses are closed. A high percentage of the feed is probably innocuous, but police and proprietors have access to the footage around the clock. Store owners are required to keep the footage for at least 30 days in secure cloud storage. What do ordinary citizens lose in the process? “One of the biggest questions was about the 4th Amendment, your right to privacy. We wanted to make sure we covered all aspects of the law. We looked into local ordinances, Supreme Court decisions, and state statutes,” Woody said.

Currently, DPD has trained 12 local installers who can set up the system once a business has passed the initial inspections to determine if it meets the requirements set by DPD. “We have to be able to control who has access to and knowledge of this tech and information; we cannot allow anyone to easily access it,” Woody said.

Part of the project includes studying its effectiveness by tracking activity within a certain radius of the original eight gas stations that helped launch the program in January and producing quarterly reports. “It’s been a great reception, as expected. We’ve had a tremendous amount of local interest and from national corporations also,” he said, though he was unable to make any figures available from the quarterly reports.

Alternative models like Project Green Light are at the heart of community policing, one of the hottest trends in public safety right now. It aims to build stronger ties between police departments and the neighborhoods they serve. Every city has its own way of applying the three tenets that define it: community partnerships, problem solving, and organizational transformation. “As a police officer who has been walking the streets of Detroit for 16 years, I can tell you that citizens used to come up to us and shake their heads at us. Now they come up to us and shake our hands,” Woody said.