A report released last year by the Fresno Office of Independent Review said the shooting was within department guidelines. “In view of the fact the suspects had used a firearm the previous day, and the weapon was outstanding, the gestures were interpreted as the suspect possibly reaching for a weapon,” the report said.

Stuart Chandler, the lawyer representing Isiah’s father , said he released the video to the news media this week because two reporters reached out after their public information requests for the video were denied by the city.

Mr. Chandler said he was repeatedly denied access to the video by a lawyer representing the city and was told by a lawyer for the day care center that its video machine was broken. He grew increasingly suspicious about how the case was being presented to the public as the city continued to deny information to reporters.

When he acquired the ambulance report, he said, he was “stunned” to find that Isiah had been shot in the back of the head, a detail that was not mentioned in official reports and indicated that Isiah likely had his back turned when he was shot.

“What was initially reported was not an accurate portrayal of what happened,” Mr. Chandler said. “It was reported as though the officer was in fear of his life. Clearly that’s not what happened.”

Isiah’s parents could not be reached for comment.

Andrew Hall, Fresno’s chief of police, said in a statement on Thursday that three review boards had concluded the shooting was justified, including the Fresno County District Attorney’s Office.

“I would like to ask the public not to rush to judgment,” Mr. Hall said, adding: “The use of lethal force in this case occurred while officers were investigating a homicide. The 16-year-old in this case was involved in the homicide with his brother and the brother was later arrested and pled guilty.”