Boston's largest police union renewed its fight against body cameras Friday, seeking an injunction to bar the city from forcing 100 officers to begin wearing the devices next week.
The lawsuit filed Friday by the Boston Police Patrolmen's Association follows months of union negotiations and a lack of volunteers for a six-month trial to test the cameras.
In court papers filed in Suffolk Superior Court, the union argues that the Walsh administration's decision to force officers to wear the cameras violates their collective bargaining agreement.
"We worked hard with officials of the city and the department to bring the citizens of Boston a body camera pilot program that made sense and protected everyone's rights," Patrick M. Rose, the union president, said in a statement. "The city and the union agreed from day one that the best way to go was to make it a voluntary program. The BPPA can't stand by and allow the city to blatantly violate the agreement it signed just over a month ago — we had to act and act quickly to prevent this miscarriage of justice."
A spokesman said Police Commissioner William B. Evans would not comment Friday because he had not had a chance to read the lawsuit. Mayor Martin J. Walsh also declined to comment because, a spokeswoman said, he, too, had not yet reviewed the lawsuit.
Advocates for body cameras called the suit the latest alarming move by the union. The group has also sought to equip its officers with more powerful guns and body armor.
"This is a police organization that has decided to demand instruments of violence and block instruments of accountability," said Matthew Segal, legal director of the American Civil Liberties Union of Massachusetts. "The fundamental question that this pattern raises is whether real police accountability is even possible in Boston."
Body cameras have come into the spotlight as a way to hold officers accountable following fatal encounters between police and unarmed black men in New York, Ferguson, Mo., and other cities.
In May, Methuen became the first major law enforcement agency in Massachusetts to adopt the cameras. They have been generally well accepted by police and residents.
The Boston Police Department typically enjoys a good relationship with residents, winning praise for sharing videos of some police-involved shootings, for even-handed enforcement during demonstrations, and for community outreach programs.
Boston began considering a body-camera program in late 2015. Last month, in what was hailed as a breakthrough, the Patrolmen's Association reached an agreement with Walsh and Evans to have 100 officers, selected from a pool of volunteers, wear the cameras for six months.
But when no officers volunteered to wear cameras, Evans announced the department would effectively force 100 officers to wear the devices.
The union filed a grievance and told the city it would be willing to renegotiate the program, if city officials agreed not to have it begin on Sept. 2, as scheduled.
But the city rejected that plea and selected 100 officers and 25 alternates, from five districts across the city, to wear the cameras. Training for the officers began earlier this week.
In its lawsuit, the Patrolmen's Association argues that the city's decision to make the program mandatory before an arbitrator can rule on its grievance makes the arbitration process a "hollow formality."
The lawsuit also cites a Rand Corporation study that found officers who wear body cameras are 15 percent more likely to be assaulted by members of the public.
The researchers who conducted the study said the increase could be a result of officers feeling more confident to report assaults once they are captured on camera.
The researchers also said cameras may make officers less assertive and therefore more vulnerable to attack.
On Friday, civil rights activists said they were disappointed, but not surprised, by the union's latest salvo.
"We renew our request that these police unions stop being an impediment to progress," said Michael A. Curry, president of the Boston branch of the NAACP. "The technology will provide significant support for the Boston police efforts around community policing, training, evaluation, and identifying issues of misconduct by Boston police officers."
Darnell Williams, chief executive of the Urban League of Eastern Massachusetts, said police command staff and rank-and-file officers had been making significant strides to improve community policing.
"While these progressive steps have become a model for the rest of the nation, it's unfortunate that we would regress or digress and go backwards, wrangling over contractual language when this is a no-brainer for what's in the best interests for both police officers and the citizens of Boston," Williams said.
Body cameras are not a panacea, Williams said, but when there are disputed interactions between law enforcement and citizens, having an audio or video record is valuable.
"We can utilize that in improving community engagement," Williams said. "It gives us additional tools to discipline or train officers to do better in the execution of their statutory power."
Earlier this month, Evans said he expected the union to challenge his decision to make the program mandatory.
"That's what the union does, they look out for their membership," the commissioner said on WGBH-FM. "Unless a court stops it, right now that's the way we're going."
Michael Levenson can be reached at firstname.lastname@example.org. Follow him on Twitter @mlevenson.