BOSTON (AP) — Boston plans to begin phasing in body cameras for its police department after a report found the devices led to slightly fewer complaints against officers and reports of officer use of force, city leaders said Thursday.

Northeastern University researchers, who examined a yearlong test of the cameras, determined they provided "small but meaningful benefits" in encounters between police and community members. As a result, Democratic Mayor Marty Walsh said the city is in talks with the police unions about expanding the devices across the force.

"If using technology like body cameras can help further improve the way we police, I'm happy to see the city's commitment to full implementation," outgoing police Commissioner William Evans said in a statement.

This year's budget includes $2 million to pay for up to 400 cameras, Walsh's office said. City officials estimate the cost for the program's first three years will be $8.5 million.

The Northeastern researchers compared a group of officers who wore 100 cameras over the course of the experiment with a similar-sized group that didn't.

The researchers found the officers who wore the cameras had 15 fewer complaints and reported nine fewer use-of-force incidents. The experts said the small number of officers involved in the experiment made it difficult to determine the cameras' true impact.

Segun Idowu, who was part of the group that pushed for police to get body cameras, said he hopes city leaders include community members in discussions about how the cameras will be rolled out.