Video footage showing the killing of a black teenager by a police officer was publicly released on Tuesday, on the same day a white Chicago police officer was charged with murder in the shooting death.

The video, which lasts six minutes and 54 seconds, captures the final moments of 17-year-old Laquan McDonald’s life on October 20, 2014 as he is confronted by two armed police officers in the middle of a Chicago street. The teenager is seen striding down the center of a two-way street and appears to be carrying a knife when the dashboard camera of a police patrol vehicle captures the moment two officers point handguns at him.

He turns briefly toward one of the officers and is then shot, the impact of the first bullet apparently spinning him around before he collapses on the street. A puff of smoke or dust can be seen rising from his body apparently as a bullet hits the ground. The camera continues to focus on his prone body as the officers, now out of frame, shoot him multiple times. An autopsy report from the Cook County medical examiner’s office showed that McDonald was shot 16 times.

Documents filed in court describing the video’s contents say for 14 to 15 seconds, the officer, Jason Van Dyke, unloads his entire gun into the teen, who is laying face down on the ground with his arms and legs jerking from the impact of the shots. Of the eight or more officers on the scene, Van Dyke is the only one to have discharged his weapon, although a colleague can be seen with his gun drawn and pointed at McDonald.

The video ends shortly after a final puff of smoke rises from the ground and one of the officers moves forward and appears to kick an object from McDonald’s right hand.

The footage was released after a day of drama in Chicago that saw Van Dyke indicted on a first-degree murder charge. He was denied bail at a hearing in the city’s main criminal courthouse hours after the state’s attorney, Anita Alvarez, announced the charges against him.

Hours later, city officials at a hastily arranged press conference condemned the actions of the officer, but warned protesters to remain calm.

“People have a right to be angry,” said police superintendent Garry McCarthy. “People have a right to protest. People have a right to free speech, but they do not have a right to commit criminal acts.”

City officials and community leaders have been bracing for the release of the video showing the 2014 shooting, fearing an outbreak of unrest and demonstrations similar to what occurred in Ferguson, Baltimore and other cities after black men were killed by police. A judge had ordered last week that the footage must be released by November 25.

“Anyone who is there to uphold the law cannot act like they’re above the law,” said Chicago mayor Rahm Emanuel at a press conference ahead of the video’s release. “I want to say one thing: there are men and women both in leadership positions and in rank and file who follow and live by that principal every day. Jason Van Dyke does not represent the police department.”

Brandon Smith, the journalist who won a Freedom of Information lawsuit leading to the video’s release, was barred from entering the press conference, as were several other journalists who did not have Chicago police credentials. Smith and his lawyer told the Guardian that they were not notified of the video’s planned release on Tuesday until seeing it on social media. While standing outside of the police headquarters, Smith’s lawyer Matt Topic was notified by officials via phone that a copy was en route to his office.

The announcement of the murder charge and slow release of details of the video before the actual dash-cam footage appeared timed to lessen the chances for violent reactions. McDonald’s family has called for calm.

“With release of this video,” Alvarez said on Tuesday at a press conference before the video’s release, “it’s really important for public safety that the citizens of Chicago know that this officer is being held responsible for his actions.”

She added that the officer’s actions “were not justified or the proper use of deadly force by an officer.”

“I have absolutely no doubt that this video will tear at the hearts of Chicagoans,” she said.

Since the death of McDonald, the Chicago police union and the lawyer representing the officer have maintained that Van Dyke felt the teenager presented a serious danger to Van Dyke and other officers.

“I can’t speak to why the [other] officers didn’t shoot,” Daniel Herbet, the lawyer representing Van Dyke, told reporters Friday, according to the Chicago Tribune. “But I certainly can speak to why my client shot, and it is he believed in his heart of hearts that he was in fear for his life, that he was concerned about the lives of [other] police officers.”

Last Thursday, a judge had ordered the dash-cam recording to be released by November 25 after city officials had argued for months that it could not be made public until the conclusion of several investigations.

The video had not been seen by anyone outside of the investigation or city officials until Tuesday, not even by McDonald’s mother, who had publicly argued against the release of the video, saying she feared violent protests.

On Monday, Mayor Rahm Emanuel called together a number of community leaders to appeal for help calming the emotions that have built up over the McDonald shooting. Some attendees of the meeting said afterward that city officials waited too long after McDonald was shot to get them involved.

“You had this tape for a year and you are only talking to us now because you need our help keeping things calm,” one of the ministers, Corey Brooks, said after the meeting.

Ira Acree, who described the meeting with Emanuel as “very tense, very contentious,” said the mayor expressed concerns about the prospect of any demonstrations getting out of control. Another minister who attended, Jedidiah Brown, said emotions were running so high that there would be no stopping major protests once the video was released.

In April 2015, the FBI announced a joint investigation with the Cook County state’s attorney’s office and the city’s Independent Police Review Authority into the shooting. Two days later, the city council approved a $5m settlement for McDonald’s family, though they had not filed a lawsuit. Chicago’s corporation counsel, Stephen Patton, said the dashboard-camera footage had prompted the city’s decision to settle.

Van Dyke is the first on-duty officer to be charged with murder while working for the Chicago police department in nearly 35 years. Since the incident, Van Dyke has been on paid desk leave while both federal and state investigations into the incident took place.

According to a freedom of information request by the Chicago Tribune, the veteran officer has had at least 15 complaints filed against him while working in high-crime neighborhoods, for accusations including using racial epithets and pointing a gun at an arrestee without justification.

In 2007, the officer was involved in a traffic stop in which he and his partner were found to have used excessive force on a man with no prior convictions, leading to a $350,000 award for damages in the case, the Tribune reported.

Chicago police also moved late on Monday to discipline a second officer who had shot and killed an unarmed black woman in 2012, in another incident causing tensions between the department and minority communities. Superintendent Garry McCarthy recommended firing officer Dante Servin for the shooting of 22-year-old Rekia Boyd, saying Servin showed “incredibly poor judgment” even though a jury had acquitted him of involuntary manslaughter and other charges last April.

The fears of unrest stem from longstanding tensions between the Chicago police and minority communities, partly due to the department’s reputation for brutality, particularly involving black residents. Dozens of men, mostly African American, said they were subjected to torture at the hands of a Chicago police squad headed by former commander Jon Burge from the 1970s to the early '90s, and many spent years in prison. Burge was eventually convicted of lying about the torture and served four years in prison.

The two ministers said black people in the city were upset because the officer, though stripped of his police powers, has been assigned to desk duty and not fired.

“They had the opportunity to be a good example and a model across the country on how to improve police and community relations and they missed it,” Acree said.

The Chicago police department said placing an officer on desk duty after a shooting is standard procedure and that it is prohibited from doing anything more during the investigations.

The Associated Press contributed to this report.