The three-minute video, recorded from a camera attached to a police officer’s chest, begins calmly.

In the middle of an afternoon, the officer walks down a pathway and onto a residential street in Montgomery County, just north of Washington. About 40 feet ahead of Officer Anand Badgujar is a man seen from the back walking in the same direction.

“Hey, big man,” Badgujar calls out, according to the body-camera footage made public for the first time Wednesday. “You need to stop.”

Things turned chaotic. The man suddenly rushed toward the officer as the officer drew his gun. “Do it! Do it!” the man yelled. The officer spun around, ran onto a yard and steadied himself. The man came at him again, then retreated down the pathway.

The encounter that followed stretched along several blocks, with the two men sometimes close, sometimes keeping their distance before ending in one of at least 33 fatal police shootings of unarmed people in the country this year. It prompted a criminal investigation of the officer, which ended last week when Howard County prosecutors, who were reviewing the case, cleared him of wrongdoing.

Among other factors, they concluded, Robert Lawrence White, 41, pushed the officer to the ground at the end of their encounter and gained control over him with a real threat to take his gun and kill him. The officer fired at least eight rounds in the final seconds.

“The tape is quite revealing,” Howard County State’s Attorney Dario Broccolino said, referring to the body-camera video. “It’s pretty clear who the aggressor was.”

“I do not want to shoot you!” the officer can be heard saying three different times. At least 21 times, White can be heard shouting, “Do it!” After being shot the first time, White fell, got up and yelled, “Do it again!”

The footage showed the men changing directions around Three Oaks Drive, a street that cuts between townhouses about a mile from downtown Silver Spring. White charged toward the officer at least three times, prompting Badgujar at various times to pull out his pepper-spray canister, police baton and handgun.

Twice, White walked close to the officer’s parked and idling police cruiser, drawing concerns from the officer that White might get in it and drive off, police said.

All the while, he stayed in contact over the radio. “He’s got his hands in his pocket,” Badgujar said, “might be a suicide-by-cop-type thing.”

Montgomery County police will continue an internal investigation that is expected to examine several issues, including whether Badgujar had a constitutional basis to try to stop White, activated his body-worn camera promptly, properly tried to de-escalate the rising tensions and was justified in firing his gun.

“Police officers are expected to investigate suspicious activity. It’s just part of our job,” said Montgomery Police Chief J. Thomas Manger, who also serves as president of the nationwide Major Cities Chiefs Association. “That suspicion has to have a constitutional basis and needs to be based on behaviors and actions, not race or ethnicity.”

White was African American. Badgujar is of Indian descent. He remains on administrative leave.

Manger declined to speak specifically about Badgujar’s assessment of White as suspicious, saying it will be part of his department’s broader internal investigation. “We will determine if Officer Badgujar acted within all of the department’s rules and policies,” Manger said.

The fatality was one of more than 590 fatal shootings by police officers this year, according to a database compiled by The Washington Post. Most of those killed were armed, including 324 people with a gun and 101 people with a knife, according to the totals.

It also was one of two fatal shootings by Montgomery County officers in a span of six weeks. On July 23, SWAT team member Edward Cochran shot a 30-year-old man who had been armed with a knife and had barricaded himself and his 3-year-old son in a bedroom. The man allegedly began lighting fires inside as the boy could be heard screaming. In the previous three years, the 1,300-member force had one fatal police shooting.

In general, a critical part of determining if a shooting was justified — and all the rounds were justified — is whether the officer perceived imminent threat of death or serious bodily harm.

“It must be objectively reasonable perception,” said Geoffrey Alpert, a criminologist at the University of South Carolina, “which requires dissecting the event to understand what the officer knew, and how and when he knew it.”

Badgujar had earlier worked for the Baltimore City police and joined the Montgomery force about two years ago. The afternoon of June 11, Badgujar, 32, had just cleared an unrelated call for service when he noticed a man walking along Three Oaks with a large rip in the back of his jacket, according to his attorney, Morgan Blackledge. That was not suspicious enough for a stop, she said, but it was enough to prompt Badgujar to look at White as he drove past him.

Blackledge said her client then saw White move his right hand into his front right pocket, as if he were armed or trying to conceal contraband. He saw White turn his left shoulder, as if to conceal the right side of his body, Blackledge said.

“He made a split-second decision — and made a U-turn to see if this person was armed,” the attorney said, adding that in doing so, Badgujar cleared the constitutional hurdle of making a “reasonable, articulable suspicion” to try to stop White and search him for a weapon.

“The easier thing to do would have been to just ride on by,” said Broccolino, the prosecutor. “But this was a police officer doing his job, seeing something suspicious.”

As the top prosecutor in Howard County, his office reviewed the Montgomery County police investigation into the shooting. The two Maryland jurisdictions have a standing agreement to review each other’s cases related to officer-involved shootings.

Merely observing a person put his hand in and out of his pocket, turn his body or make a sudden movement might not have been enough for a proper stop, said David Felsen, a longtime criminal defense attorney in Montgomery County and an instructor at American University’s law school.

“An officer is allowed to have suspicions. But it’s got to be more than a hunch,” Felsen said. “This sounds like a hunch. All you really have is a guy acting weird.”

Still, the unpredictable scenes encountered by officers, Felsen noted, are evident in the case with White.

According to the video, after Badgujar called out, “Hey, big man, you need to stop,” White wheeled around and came after him, getting so close that the officer turned to run to create distance between the two.

“That was clearly an assault,” Felsen said. “And at that point, the officer now had probable cause to arrest him.”

After separating himself from White, Badgujar called into his radio, asking to elevate his earlier request for backup to priority status. White came at him again and appeared to strike the officer, who fired pepper spray at White before White jogged off to a footpath.

The officer followed White, adding a more detailed description into his radio for backup officers on the way. “It’s going to be black a male, mid-age, 6-foot, blue jacket with a hoodie, ripped in the back,” Badgujar said. “Black shorts, black sneakers.”

As captured on the video, a civilian appeared in front of the officer as White walked by her. She stood next to a parked car with an open back door and appeared to be putting a baby in or out of a car seat.

White turned back toward the officer.

“Get in your car and stop following me!” he shouted. “If you’re going to do it . . . do it!”

Badgujar veered, shielding himself behind another car, with his gun drawn. White reversed direction, walking past the SUV again as the woman could be seen darting off with the baby in her arms.

A distant siren signaled the pending arrival of the first backup officer. Badgujar jogged around White to get to the idling police cruiser and reached in to shut off the engine.

“Do it!” White yelled, his right hand appearing to go into his pocket. He bent into a crouch, taking a half-dozen steps toward the officer.White looked to his rear, seeing the arrival of the second officer.

“Face shot!” White said as Badgujar backed away.

White suddenly closed in on Badgujar, striking him as the officer fell backward and fired one round.

“Ahh!” White yelled, falling from an apparent leg wound but getting back up.

White closed in on the officer again, his hands going on Badgujar’s shoulders.

Badgujar fired two more rounds as White swung at him and threw two punches.

At least five more rounds are fired by Badgujar, the burst of gunfire so rapid that it is difficult to hear precisely how many before White falls away, rolls on his back and is motionless on the pavement.