Police officers who wore body cameras were less likely to have complaints of wrongdoing filed against them, according to preliminary findings of a monitoring equipment program that is being tested by Boston police.

The one-year pilot found that 12 fewer complaints were filed against a group of officers equipped with the body cameras over the one-year period. The totals were 17 complaints against the roughly 120 officers who participated in the program at some time, compared with 29 against a control group of 120 officers who did not wear cameras.

The review did not find any correlation in the number of ­­use-of- force reports that were filed by officers who had to use force during an encounter, compared with the control group, the Police Department said. Eight reports were filed by officers who wore body cameras, compared with 15 by officers who did not have them.

Researchers said in the preliminary review that the program may generate small benefits to the civility of police-citizen encounters, adding that officers who wore body cameras in general received fewer citizen complaints and generated fewer use-of-force reports.

Advocates of the body cameras viewed the preliminary report as a positive sign for their cause. But in a statement, the Police Department said the numbers do not suggest any significant correlation between the use of body cameras and the filing of citizen complaints.

Citywide, the number of complaints has decreased by 44 percent, from 360 in 2013 to 199 in 2016. The department said that use-of-force reports have decreased by 54 percent since 2013, while arrests have dropped 32 percent during that same period.

The city’s police union had initially opposed body cameras, agreeing to the pilot after negotiations with the city.

Mayor Martin J. Walsh has never committed to the program, saying only that he wanted to see the results of the review. He said last week on Boston Public Radio that he was “not convinced yet’’ that cameras would be appropriate.

In an interview Wednesday, Police Commissioner William B. Evans welcomed the report for showing a relatively low number of complaints against officers, and he thanked them for participating “even if the results may be minimal.’’ But he said he looks forward to the final results, due in June, which will examine general police practices, police interactions in the community, and whether the expansion of the body camera program is appropriate.

“We just want to look at all the pros and cons of it,’’ he said. “There’s a lot of factors other than putting them on officers that have to weigh in on the final decision.’’

In the pilot, 100 cameras were placed on patrol officers in five police districts, and plainclothes officers in the Youth Violence Strike Force, which tends to gang matters. There were 281 participating officers in total, including in the control group, and they typically worked day and evening shifts. The age, race, sex, and experience levels of those in the pilot program were equitable to those in the control group, officials said.

The review was commissioned in January amid national tensions in police and community relations, following several high-profile national incidents of questionable police tactics — including fatal shootings of unarmed men by police officers — that were caught on video.

City Council President Andrea Campbell, who has pushed for the consideration of a body camera program, said that the preliminary findings demonstrate an “overall positive response.’’ She urged the city to continue to look at the program, including costs, and whether the cameras could be implemented in phases.

“I do think body cameras should be one tool, among many, that we use as a part of a larger public safety strategy to improve interactions between officers and civilians and vice versa, to help address issues of violence, and to increase accountability for the Police Department,’’ Campbell said.

Segun Idowu, one of the founders of the Boston Police Camera Action Team, which pushed for the consideration of the program, also welcomed the report’s findings. But he cautioned against coming to any conclusions until the full report is released.

Idowu said his group wanted a more thorough examination of police interactions with the community and the ways cameras could benefit those interactions.

“What we’re really looking for is a report that talks about what in the policy works, what didn’t work,’’ he said. “What was people’s reaction to being on camera, officers’ experience on camera — all factors’’ that could shape policy, he said.

The analysis was conducted by Northeastern University criminology researchers Jack McDevitt and Anthony Braga.

In their report, the researchers acknowledged that similar reviews of body camera programs nationwide have had different results, with some communities finding significant change.

Rialto, Calif., reported a 90 percent reduction in complaints and a 50 percent reduction in use of force reports, for instance, while other municipalities found no significant change.

The researchers said their review in Boston was made more difficult by the relatively low number of police officers who participated in the program and the relatively low number of complaints against Boston police in general.

But they added: “The preliminary findings of this randomized controlled trial suggest that the placement of [cameras] on BPD officers may generate small benefits to the civility of police-citizen civilian encounters in Boston.’’

Milton J. Valencia can be reached at milton.valencia@globe.com. Follow him on Twitter @miltonvalencia.