This story was last updated at 10:28 p.m.

D.C. police have released video of an officer fatally shooting 18-year-old Deon Kay Wednesday afternoon in Congress Heights.

In body camera footage, an officer exits his police car and approaches a parked car in the parking lot of an apartment building.

One person, who has not been identified, ran, police said. In the video, the officer chased after the person fleeing down a hill and yelled “don’t move” at least three times. The officer turned around, encountering Kay, who held a gun in his hand, the video shows.

In the video, Kay briefly raised the gun. The officer then shot him in the chest. Officials said Kay threw the gun nearly 100 feet.

City officials on Thursday identified the officer who shot Kay as Alexander Alvarez. They said Alvarez joined the Metropolitan Police Department in 2018.

The police department released two versions of the video. The first is four minutes and 19 seconds. It begins with a police department narration and ends with footage of the shooting in slow motion.

The second version is nearly 11 minutes and does not appear to be edited except for the blurring of faces. There is no audio in the first two minutes of the longer video because audio only records when the cameras are activated by the officers.

After the shooting, Alvarez said “shots fired” twice, according to the video.

Alvarez then searched for the gun in the grassy area and playground near the parking lot where he shot Kay, the footage shows, and described the incident to other officers who arrived on the scene. Police said they recovered a gun and took it as evidence.

Newsham said police knew two people in the car, including Kay. It’s unclear if Alvarez specifically knew Kay.

After the shooting, another officer asked Alvarez if Kay was a juvenile. “I don’t know if he is…I don’t know,” Alvarez said in the video. “I mean, I think he was like a year ago, I think.”

DCist/WAMU could not find any court records related to Kay. Family members said he turned 18 last month. 

City officials said he attended Ballou STAY Opportunity Academy but did not know if he was enrolled at the alternative high school this academic year.

The shooting happened shortly before 4 p.m. Wednesday in the 200 block of Orange Street SE. The officers involved in the shooting were placed on administrative leave, which is standard department policy.

“We are in the infancy stages of an investigation,” Metropolitan Police Department Chief Peter Newsham said at a press conference Thursday. “All we have is some statements and a video. There is a lot of work yet to be done before we come up with any conclusions.”

Police said they arrested two other people on the scene: Marcyelle Smith, 19, was charged with carrying a firearm without a license and Deonte Brown, 19, was charged with “no permit,” which refers to operating a vehicle without a license.

Officials said police saw four people in a car live-streaming on Instagram with guns. Police responded within 45 minutes.

Before police released the footage, Black Lives Matter D.C. said in a tweet directed at Mayor Muriel Bowser and Newsham that “a community is waking up to one less Black future to build and hurting.”

An emergency measure the D.C. Council passed in June requires the Metropolitan Police Department to release video from body-worn cameras within five days of a fatal shooting. It also requires the city to release the names of the officers involved. Under the law, families of the victims can choose to withhold the video from public release.

Local officials quickly responded on social media after the video was released.

D.C. Attorney General Karl A. Racine said in a tweet that his office is closely following the investigation.

“To those rightfully demanding answers today: we hear you,” Racine said. “We are going to continue our work to stop violence through community-driven violence interruption programs.”

David Grosso, an at-large member on the D.C. council, called the police killing of Kay a tragedy and said the public deserves answers from the police department.

“His death is a failure of our outdated approach to community safety,” Grosso tweeted.

On Thursday night, Councilmember Trayon White held a virtual community meeting about public safety and community violence intervention, and began the meeting with a moment of silence for Kay.

“To me, it doesn’t matter how he died,” said White, who represents Ward 8, where the shooting happened. “The fact is, a young man lost his life here in our community yet again.”

Dana McDaniel, deputy director of the city’s Office of Neighborhood Safety and Engagement, said she worked with Kay in her previous role with D.C.’s Department of Youth Rehabilitation Services.

“I’m sure many of us on this line have had connections and contacts to the victim and his family,” McDaniel said. “He indeed was a wonderful young man to work with.”

Daisia Robinson, an outreach worker with Cure The Streets, a public safety program in the D.C. Attorney General’s office, said Kay’s death hit her hard.

“Losing Deon, that was real close to me,” said Robinson. “I know how it feels to feel like you don’t have somebody to look up to, or someone to talk to.”

For years, Black D.C. residents have criticized tactics police use to stop and search people for illegal guns and say law enforcement routinely violate their civil rights. A WAMU investigation in 2018 found that nearly 40% of gun possession cases in D.C. Superior Court were ultimately dismissed by a judge. Officials with the police department have defended its approach, saying that confiscating illegal guns is key to reducing violence.

Monica Hopkins, executive director of the ACLU of D.C., said in statement “the time is overdue” for D.C. to focus on solutions to violence that do not involve police.

“The tragic shooting and death of 18-year-old Deon Kay is the logical conclusion of a policy that not only meets violence with violence, but actually escalates and incites it — especially in our Black communities,” Hopkins said. “In addition to being unsuccessful in reducing gun violence in the District, the Metropolitan Police Department’s tactics ignore the complexities of why young people like Deon may have guns to begin with.”

After the shooting Wednesday night, protesters gathered outside the 7th District police station and another group demonstrated outside Mayor Muriel Bowser’s house. Early Thursday morning, members of the environmental advocacy group Sunrise Movement D.C. also protested in front of Bowser’s house.

“If you don’t defund the police, then you shouldn’t bother running for reelection,” one protester said into a megaphone.

In July, the Metropolitan Police Department released footage of police killings of three Black men in 2018 — Marqueese Alston, D’Quan Young and Jeffrey Price. The last fatal shooting by D.C. police occurred in September 2019.

This story has been repeatedly updated with new information about Kay, officials’ response, comment from the ACLU, and details about the shooting.

Martin Austermuhle, Jenny Gathright, and Colleen Grablick contributed reporting.