BOSTON — Surveillance video released Monday of the fatal shooting of a Boston man suspected of plotting to kill police officers shows him appearing to move toward officers before they open fire.

The blurry video shows a man identified by police as Usaama Rahim, 26, walking through a CVS parking lot on his way to a bus stop June 2 in the city's Roslindale neighborhood.

Officers, who authorities say were in plainclothes, approach Rahim but back up as Rahim advances toward them in the parking lot.

The officers then draw their firearms, and Rahim, who is mostly obscured by a light pole during the altercation, falls to the ground.

It is not clear from the video what specifically led officers to draw their weapons or which officers discharged them. Police have said two officers — an FBI agent and a police officer — fired three shots.

Officials released the original version of the video, which comes from a nearby Burger King restaurant, as well as a version that zooms in on the encounter.

Police Commissioner William Evans said Monday that the video shows officers "made the right call." He says police used deadly force after giving Rahim, who is black and Muslim, "multiple chances" to drop a military-style knife.

Evan says the video shows that Rahim was "well within striking distance" of one of the officers and that officers were clearly backing away.

"We averted a serious tragedy that day," he said. "I don't think at this point he was going to go down very easy. ... We can second-guess this, but it unraveled so quickly. I believe my officers acted responsibly."

Suffolk District Attorney Daniel Conley said release of the video before his office's investigation is complete comes as the public has demanded greater "transparency and accountability" when officers use lethal force.

Media and technology, he said, have also made it easier for "rumor, speculation, and inaccurate information" to spread.

"For this reason, we've agreed to release certain video evidence earlier when it can help illuminate the facts, and when doing so won't compromise the integrity of the investigation," he said.

Authorities last week showed the video to black and Muslim community leaders and Rahim's family. They promised to release the video publicly after Rahim's burial, which was Friday.

Darnell Williams, president of the Urban League of Eastern Massachusetts, said the video largely corroborated the police account of the shooting. But Abdullah Faaruuq, an imam at a Boston mosque where the family prayed, said it was "inconclusive" because it's not clear if Rahim had a knife in his hand.

Ibrahim Rahim, who leads a mosque in Oakland, California, said on social media in the hours after the shooting that his brother had been shot in the back. But the family has since recanted those statements, saying they were based on erroneous third-hand information.

Ibrahim Rahim and a lawyer for Rahim's family did not immediately respond to requests for comment Monday.

Authorities have said the FBI and Boston police's Joint Terrorism Task Force had Rahim under 24-hour surveillance.

They say officials intercepted conversations between Rahim and his nephew, David Wright, that suggested Rahim, a private security guard, planned to carry out an attack on police officers soon.

Rahim had also talked about beheading anti-Muslim blogger Pamela Geller before deciding to target "boys in blue," they say.

Wright, 24, of Everett, was arrested last week on a charge of conspiracy with intent to obstruct a federal investigation. He's being held in custody pending a June 19 hearing.