Police on Sunday identified the teenager as Brett Rosenau, 15, and said preliminary autopsy results determined the cause of death was smoke inhalation. In a statement, the department said “no shots were fired by anyone” during the standoff, during which officers arrested a man they wanted, Qiaunt Kelley, 27, on a parole violation warrant. “I know many people in our community are hurting right now and I appreciate everyone’s patience while this incident is thoroughly investigated,” Chief Harold Medina said in the statement. “If any of our actions inadvertently contributed to his death, we will take steps to ensure this never happens again.” Mr. Rosenau’s family said in a statement that it supported a request by the American Civil Liberties Union of New Mexico that the state attorney general, Hector Balderas, investigate the death. In the statement, the family described Mr. Rosenau as a smart and funny teenager who enjoyed football and baseball and building and rebuilding bicycles and who was “always interested in creating something new.” “The conduct of the police on July 6, 2022 can only be described as tragic and completely avoidable,” said the statement released by the family’s attorneys, Carey Bhalla and Taylor E. Smith. “The police had every opportunity to save Brett’s life, but instead chose inaction. Brett’s family and community are forever missing their son, brother and friend.” Mr. Balderas said in a statement that, “I am troubled by the recent loss of life of a young teenager in our community and my office will provide assistance to ensure that appropriate action is taken during this law enforcement operation.” . The episode, which began Wednesday and ran through early Thursday, renewed scrutiny of the department’s history. This file was the subject of a 2014 agreement with the US Department of Justice to introduce reforms and oversight of police use of force tactics, accountability, education and community involvement. The settlement was reached after the Justice Department found a pattern of excessive police violence: 23 people were killed and 14 injured in police shootings over a four-year period. Under the agreement, the police are required to report details of the investigation into Mr. Rosenau’s death to the Justice Department, the police said. They will also release video from officers or drones taken during the standoff, the department said. The release of the statement on Sunday was at least the second time in two days that the chief sought to defend his department and appeal for calm. On Thursday night, dozens of people gathered to protest the death of the teenager, who was black, The Albuquerque Journal reported. At a news conference last week, Chief Medina urged the public to wait “before making a decision that affects the quality of our city.” He said a launcher used to fire tear gas and powder canisters at the home may have led bystanders to believe shots had been fired. “We have no indication that shots were fired from the Albuquerque Police Department,” the chief said. The episode unfolded late Wednesday as detectives searched for Mr. Kelley. Mr. Kelley had violated the terms of his prison terms for armed robbery and vehicle theft and was also wanted in connection with a fatal shooting, a recent armed robbery and another shooting in which someone fired an automatic weapon at officers, the department said. Police located him at a home in southeast Albuquerque, the most populous city in New Mexico with a population of more than half a million. They saw a gun in the car he was riding in and determined the motorcycle he was working on at the residence was stolen, the police release said. Mr. Kelley entered the house. Mr. Rosenau, who the police were not looking for, followed Mr. Kelley into the house, the police said. Law enforcement officers “tried for several hours to get them to leave peacefully,” the statement said. Officers used a drone and robot to determine who was inside. Sgt. Michael Jones, a regular officer, said during a press conference last week that officers deployed a Tri-Chamber Flameless Grenade device, commonly used in crowd control, that disperses tear gas and powder to make the environment “uncomfortable ». The disturbance ended when officers noticed smoke coming from the home, the department said. As firefighters arrived, Mr. Kelley appeared and was arrested and later treated at a hospital for burns. Mr. Rosenau was found dead inside the home, the police said. Albuquerque Fire Rescue is investigating the cause of the fire, which will likely last about two weeks, police said. Defense Technology, which makes the Tri-Chamber Flameless Grenade device, says on its website that it “provides the option of delivering a pyrotechnic chemical device indoors, maximizing the effectiveness of the chemicals through heat and vaporization, minimizing or negating the potential for fire in structure.” The police statement said Chief Medina acknowledged the possibility that “devices used to introduce irritants into the home may have caused the fire.” He added that “there have been no reported fires in the many years of use in Albuquerque.” The ACLU of New Mexico said in a statement that the events “raise real questions about the training and experience of APD’s SWAT team and the dangers involved in the inappropriate use of tear gas.” Barron Jones, senior policy strategist at the ACLU of New Mexico, said in the statement: “The loved ones of Rosenau deserve answers, and our community needs to be confident that proper accountability will be applied to deadly police encounters like this one.” Michael Levenson contributed reporting. Susan C. Beachy contributed research.