In an effort to combat underage drinking, Cambridge is now participating in a nationwide program that places undercover law enforcement officers in retail establishments that sell alcohol.

The program, known as “Cops in Shops,” is a project conceived by the Century Council, a non-profit organization based in Washington that “promotes responsible decision-making regarding beverage alcohol and fights alcohol abuse,” according to its website.

Locally, the Cops in Shops program is administered by the Cambridge License Commission (CLC). The storefront windows of several Harvard Square establishments now display the campaign’s posters, which feature a picture of a police badge and a warning to underage customers that they may be arrested if they attempt to purchase alcohol inside.

“Cops in Shops is designed to be a cooperative program between law enforcement and retailers,” said Ronald E. Engle, director of traffic safety for the Century Council. “It’s designed to stop underage alcohol purchases and also to stop purchases by adults who are purchasing for kids.”

According to Engle, the program also functions as a deterrent. “The concept is that if it’s apparent that you’re stopping the offense at the source, that the word gets around, and it reduces the number of underage people who try to buy alcohol products,” he said.

CLC Executive Officer Elizabeth Y. Lint said that local colleges were a major consideration in the city’s decision to participate in the program.

“Cambridge certainly has many students, so as everyone’s coming back to school, it was our hope...to do whatever we could to help curb underage drinking,” she said.

Engle said Cops in Shops has been used in 42 states and on several college campuses. The University of Maryland, for example, had officers in its Department of Public Safety monitor stores under the program, he said.

Lint said that the undercover “Cops in Shops” actually consist of both CLC investigators and Cambridge Police Department officers.

Engle said the Century Council creates training materials for participants, and added that the organization also provides the posters displayed by the retailers participating in the program.

Cops in Shops is “just an added level of protection,” according to Josh Eaton, general manager of Cardullo’s Gourmet Shoppe on Brattle Street, a store that is participating in the program.

“Being right next to a college, we do have a lot of young people buying alcohol, for sure,” Eaton said. “Should we sell alcohol to a minor, there’s a fine, and we do lose our license for a few days...that’s something we want to protect ourselves against.”

Eaton added that the program also helps maintain the vigilance of the staff. “It’s a reminder to employees here that they need to be diligent about checking IDs,” he said.

Lint said the nature of Cops in Shops is simple and its goal should be clear. “An undercover officer is placed inside the stores,” she said. “If someone who is underage attempts to make a purchase [of alcohol], they’re going to get arrested.”

—Staff writer Matthew S. Lebowitz can be reached at mslebow@fas.harvard.edu.