Two days after Boston Police Commissioner William Evans’ announced he was implementing a body camera pilot program, local civil rights groups have released a policy proposal for the technology.

The proposed policy outlines protocols for how officers should operate body cameras as well as how police departments should store video footage, make data available to the public and enforce the policy.

The ACLU of Massachusetts, the NAACP in Boston and the Boston Police Camera Action Team (BPCAT) say they applaud the Boston Police Department’s move to implement body cameras. The groups joined together to release a proposed policy Thursday that they hope will serve as a “model policy” for police departments across the state.

“The locations where they have adopted body-worn cameras, there has been a significant decline in complaints about police abuse,” said Rahsaan Hall, the director of the ACLU’s racial justice program. “So we’d want to see if that holds true for Massachusetts.”

Hall, who helped craft the proposed policy, said the main objective was to address privacy, transparency and accountability.

The privacy issue in particular also raises many questions about surveillance and civil rights — all core issues the ACLU works to protect. But body cameras seem to be a special case for the organization, which is pushing for the technology to be adopted.

“We’re certainly concerned with privacy rights; it’s a hallmark of our organization,” Hall said. “We’re also concerned with due process rights and equal protection rights and to the extent that those rights are violated by law enforcement. We want to be able to show that. We want to be able to prove that. We want to be able to provide redress for that.”

The proposed policy calls on officers to activate the cameras (both audio and video) whenever they respond to a call or are conducting an investigation, and to leave them on until an encounter was over. The policy also says officers should notify people when they are being recorded and in some cases ask the person if they want to be recorded — for example, before entering a private residence without a warrant, when interacting with a victim or when a person is trying to report a crime anonymously.

The proposed policy would prohibit officers from using body cameras for surveillance or recording activity that is unrelated to an investigation.

“We don’t want people just taped when they’re exercising their free speech right or freedom of expression or their right to organize or freedom of assembly,” Hall said.

The policy would also ban the use of body cameras in elementary or secondary schools unless responding to an imminent threat to life. It also says video that is improperly gathered must be destroyed immediately.

The proposal calls on police departments to store body camera footage for six months before permanently deleting it. In some instances, departments would have to store videos for at least three years — for example, if there was any use of force, a complaint is filed about the encounter or for felony level crimes. Video would also have to be stored for at least three years if an officer or subject of a body camera video requests it. Body camera video could also be made public through a public records request or for law enforcement purposes under the proposal.

Enforcement of these protocols would fall to the police departments under the proposal. The proposal says those who fail to comply with the policy should face “appropriate disciplinary action.” That would need to be determined by the management structure and disciplinary measures already in place at police departments, Hall said.

“This is a framework for them to use to contemplate how to use the body-worn cameras,” Hall said.

Local activists have been raising the issue of bringing body cameras to Boston since last year. The ACLU recommended using the technology last fall after a report found blacks were disproportionately stopped by Boston officers. Last month, the Boston City Council also took up the issue.

Commissioner Evans said earlier this week that he hopes to have the first body cameras on Boston police officers “within the next couple of months.” Mayor Marty Walsh supports the pilot program and said body cameras “could be a valuable investment in our police force.” In a statement Thursday, the mayor’s spokeswoman Bonnie McGilpin said Walsh “looks forward to reviewing the ACLU’s proposal.”

In a phone interview, police spokeswoman Officer Rachel McGuire said the department is aware of the ACLU’s proposal and Commissioner Evans will be taking suggestions as he moves ahead with the pilot program.

“We’re not just going to take the ACLU’s policy and implement that,” McGuire said. “It’s a suggestion and the commissioner will take it into consideration.”

Body cameras became part of a national dialogue on police-community relations in the wake of Ferguson and other high profile cases where unarmed black men were killed by police.

Many believe body cameras would provide greater transparency, improve community relations and help resolve conflicting accounts of police encounters. But the technology also raises concerns about privacy, costs, data storage, policy and logistics.

Cities across the country have already launched body camera pilot programs — including New York, Los Angeles, Chicago, Philadelphia, Seattle and Washington, D.C. And in Massachusetts, a few cities are testing them out, including Worcester, Springfield, Methuen,Abington and Gill. Lowell police and State Police are also looking into the technology.