As cases of police misconduct continue to make headlines around the country, the Boston Police Department plans to pilot the use of body cameras beginning in late spring, but it won’t be the first in the state: In Erving, Mass., body cameras are already standard operating procedure.

Approaching a convenience store where a man is having a seizure, Erving Police Chief Christopher Blair hits a button on a camera attached to his uniform, just under his left breast pocket. In the store, a man, maybe in his 60s, lies on face down on the ground in front of the register.

“Sir can you hear me?" Blair asked. "Can you hear me?”

Blair rolls the man over and checks his head, then turns to the cashier.

"Did he hit his head at all, did you see him go down?" Blair asked.

After paramedics take the man away in an ambulance, Blair heads back to the station, removes the camera from the brace attaching it to his uniform, and pops the camera into a cradle, A minute later, the whole thing is right there on his computer screen.

On the screen, Blair’s arms reach forward from either side of the image as he rolls the man on his side.

“You’re getting a point-of-view vision of everything I’m seeing and doing, basically,” he said.

Blair first saw the need for body cameras about 20 years ago, after he frisked a woman in a stolen car, and she lied in a complaint that he’d inappropriately touched her.

“It really bothered me to think that someone could make allegations against you like that, against you as a police officer, and you have no recourse whatsoever,” he said.

The technology finally got good enough that last year the tiny Erving Police Department bought five body cameras at $900 a piece, Blair said, paid for by the department’s insurance company.

“I think it protects them, it protects us," he said. "It makes us behave better as police officers. If we’re doing everything right and we’re doing a good job, people can’t sue us.”

There’s a learning curve for using the cameras. On his own second day with one, Blair responded to a call for a loose dog—not something he thought he'd need to record.

“I get out of my cruiser, and the loose dog turned out to be a 100-pound pit bull and it attacked me," he said. "It came right at me running at a full run, it was in mid-air jumping as I pulled my Taser and shot the dog at point blank range."

The cameras can actually capture video thirty seconds before the record button is hit, but by the time Blair got around to it, he’d missed the attack. A hearing followed the incident, during which Blair said the video would have been helpful.

“I told my guys after that happened, I said ‘Guys, when you get the call, turn the camera on. Don’t wait to get to the call and then have something happen and forget,’” he said.

As a chief, Blair says the cameras give him the chance to see what actually happened if there’s a complaint about one of his officers. But the cameras can miss things like body language, so he advises his officers to narrate what’s happening.

“Say ‘Sir, stop resisting, I can feel you tense your arm up,’" he said. "You almost have to verbalize it back to them, so that we know what’s happening on the video."

He acknowledges that people who are skeptical of the interaction might believe the officer was just saying that for the camera.

“No doubt about it," he said, laughing. "No matter what you do, we’re always wrong, you know.”

Since Blair was the first chief in the state to adopt cameras, he had to develop a policy for their use himself, and he says he thought a lot about privacy. Who would have access to the videos?

“I say that if it’s inside somebody's house, they have a right to privacy," Blair said. "I’m not going to release that to just anybody. I’ll release it to that person or the persons involved in the incident, but I’m not going to release it to the guy down the street or the next door neighbor or something like that.

For now, it's up to Blair to determine who gets that footage and who doesn't.

"Somebody has to regulate this," he said. "Until the legislature steps in and makes a law that protects us, we’re going to have to test the water with this stuff.”

The state’s wiretap law makes it difficult to use video evidence in court if it’s secretly recorded. Blair says they try to tell everybody they talk to that the camera is rolling. The state Legislature is discussing a law that would exempt law enforcement officers in uniform from the wiretap statute.

"That needs to be passed.”

That's especially true, he says, as more departments start using the cameras. Blair’s happy to hear Boston’s going to try it out soon, and he has some advice for them.

“Once you start this program, you have to cut your officers some slack," he said. "You really have to start off slow and understand that the guys are going to make mistakes. They’re going to accidentally not turn the thing on, they’re going to forget to turn it on. The batteries are going to die.”

But once those kinks are worked out and the officers get used to them, Blair thinks they’ll embrace body cameras. For the most part, Blair says, the officers are doing a phenomenal job, and he thinks as body cameras become more commonplace, they’re going to demonstrate that.