ST. PAUL — The images had transfixed people around the world: A woman live-streaming the aftermath of a police shooting of her boyfriend, Philando Castile, and narrating the searing, bloody scene that was unfolding around her.

On Friday, a jury here acquitted the Minnesota police officer, Jeronimo Yanez, of all charges in shooting, which happened in July 2016 and left Mr. Castile dead, raising the national debate over police conduct toward black people. Officer Yanez, an officer for the suburb of St. Anthony, had been charged with second-degree manslaughter and endangering safety by discharging a firearm in the shooting.

The verdict was announced in a tense courtroom here late Friday afternoon, after five days of deliberations, and the officer was led quickly out of the courtroom, as were the 12 jurors. Mr. Castile’s family, which had nervously watched the proceedings from the front row, abruptly left as well.

“My son loved this city, and this city killed my son,” Mr. Castile’s mother, Valerie, said as she stood on a corner outside the courthouse afterward. “And a murderer gets away. Are you kidding me right now?”