Correction: This article incorrectly attributed to D.C. Police Chief Cathy Lanier information about the emergency response. Officials with the mayor’s office, not Lanier, said police were dispatched at 4:04 a.m. and arrived at 4:06 a.m. Police say those times are incorrect and that officers were dispatched at 3:58 a.m. and arrived at 4:02 a.m.

Authorities released body camera video of officers giving chest compressions to a handcuffed man who had been detained by security guards and later died. It is the first time D.C. has released police body camera video. (DC Metropolitan Police Department)

Mayor Muriel E. Bowser on Tuesday ordered the release of a video from a camera worn by a D.C. police officer that shows a private security guard with his knee pressed to the back of a 27-year-old man who had been restrained and whose death has been ruled a homicide.

Bowser’s decision came just hours after the D.C. Council unanimously passed legislation clearing the way for the city’s body-camera program to become permanent. It also came after months of wrangling by D.C. officials over whether video captured by police body cameras should be released to the public and whether such a release would violate privacy or possibly compromise ongoing investigations.

But Bowser, who initially had opposed making such videos available to the public, surprised many by ordering the release of the video showing the restraint of Alonzo Smith.

Smith, a teacher at a private school in Virginia, was restrained by a D.C.-licensed private security guard at the Marbury Plaza apartments on Nov. 1. The video released on Tuesday does not show Smith, who suffered a heart attack, struggling with security guards. But the District’s chief medical examiner, Roger A. Mitchell Jr., said the knee press was consistent with the victim suffering “compression to the torso,” which he ruled had contributed to the death. And Police Chief Cathy L. Lanier said the tactic used to restrain Smith was “not how we train.”

Both Lanier and Mitchell also said for first time that Smith was involved in a significant struggle before he was handcuffed and passed out in a stairwell of the apartment complex in Southeast Washington. They cautioned that details of that struggle and Smith’s initial encounter with the armed security guards are not yet known.

Alonzo Smith, 27, died Nov. 1 after being found handcuffed by special police officers in an apartment building in Southeast Washington. (Family photo)

“We do not have answers to exactly what happened,” Lanier told reporters Tuesday after making public the 10-minute body-camera video, which starts when two D.C. officers arrived at the distress call. It was the first time D.C. officials have released body-camera video since a pilot program began many months ago for 400 officers in two of the city’s seven police districts.

“The video does not show how this man died, nor does it confirm whether the use of force was justified or reasonable,” Bowser (D) said at the news conference. She ordered that the video be posted on the police department’s Internet site after the council unanimously passed the legislation clearing the way for the pilot program to become permanent. Bowser said 2,800 officers should be wearing cameras by the end of summer.

Officials said that a request for the video in the Smith case would ordinarily be denied under a public information request, because the U.S. attorney’s office is still reviewing the case for possible charges. The legislation allows for Bowser to make an exception and release a video, even if it could otherwise legally be withheld, if she deems it “in the public interest.”

The mayor said that the Smith case holds “significant public interest” and that police also are hoping it could prompt additional witnesses to come forward. District officials said body-camera videos in all police-involved shootings, in-custody deaths and in cases­ in which people suffer serious injuries in police interactions will be reviewed by the mayor and her legal team. They will decide whether to make the video public, erring on the side of release.

“It enhances transparency and trust between the community and the police department,” Bowser said Tuesday. Representatives from the company that employes the guards involved in Smith’s case, Blackout Investigations, did not return calls Tuesday.

Smith is the second man to die in the District this year after a confrontation with armed private security guards, who are called “special police” and who have authority to arrest suspects within their geographically assigned areas. The other man who died was 74, and he suffered a broken vertebra while being restrained by guards outside MedStar Washington Hospital Center. An autopsy in his case is pending.

Smith died at a hospital about an hour after he was restrained at the apartments in the 2300 block of Good Hope Road SE. His relatives said he might have been there to visit a woman. Police said four residents called 911 to report a man racing through the halls, shouting and banging on doors.

Lanier said officers were dispatched at 3:58 a.m. and arrived at 4:02 a.m. The video shows the officers racing into the building and toward a stairwell landing halfway between the first and second floors. The opening moments of the video show Smith, clad in pants but no shirt, on his stomach and handcuffed in the back. Two guards were over him, one near his head, the other with a knee in Smith’s back. Labored breathing can be heard, which police said Tuesday was from one of the guards who, they said, had just been in the struggle.

Lanier said one of the guards told an officer that they thought Smith was high on PCP. That officer then left the scene, called for an ambulance and went to his car to retrieve additional restraints.

Lanier said police put on more restraints and then took them off, rolled Smith onto his back and began CPR. Most of the video is from the camera on the officer performing chest compressions. Several times, he is heard shouting, “Come on, man, wake up.” After about seven minutes, an officer says, “We got no pulse.”

The first paramedic arrived at 4:11 a.m. One officer is heard on the video telling the medic that the “guards had to secure him because he was running and on PCP.” The medical examiner reported finding cocaine in his system but gave no indication of finding PCP.

Authorities urge anyone who saw what happened to Smith or knows anything about the case to call police at 202-727-9099 or the U.S. attorney’s office at 202-252-7130. Officials said a second D.C. police officer also was wearing a body camera during the Smith call and that will also be made public soon.