Former East Pittsburgh police officer Michael Rosfeld was found not guilty Friday night at the Allegheny County Courthouse in Pittsburgh.

The verdict ends a contentious case that has divided the region for nine months. It did not end the controversy.

The trial began Tuesday morning and the jurors weighed evidence, testimony and arguments for four days. Jurors then had to decide whether Rosfeld was justified when he killed Antwon Rose II, who 13 minutes earlier had been in a car during a drive-by shooting in North Braddock.

Minutes after the verdict became known, a crowd gathered on the steps of the courthouse, proclaiming Rose was a freedom fighter. Shortly before 9:30 p.m., people outside the courthouse began singing “What side are you on my people?” The response: “The freedom side.”

When they left the courthouse, Rose’s mother and sister showed no emotion as they left on Ross Street. They were escorted by a deputy sheriff and entered a private car to leave the area. As television cameras recorded the family leaving, an unidentified woman bystander said, “It’s crazy. You’re taking pictures but you can shoot somebody on camera and not be convicted.”

“The verdict was too fast,” said Rose’s aunt, Carolyn Morrison of Rankin, as she entered the courthouse prior to the verdict. “The trial was too fast. The verdict was too fast. It was all too fast.”

Metal barricades lined the sidewalks around the courthouse to keep people out of the street. The city had prepared for the verdict by deploying Public Works snow plows and police officers around the courthouse in the city’s downtown.

The jury got the case at 4:38 p.m., with the options of a not-guilty verdict, or first-degree and third-degree murder, as well as the lesser charges of voluntary and involuntary manslaughter as part of their deliberations. The verdict came less than five hours later.

Under Pennsylvania law, an officer is justified in using force when he believes it is necessary to prevent death or serious injury to himself or others, or if he believes it necessary to prevent a suspect’s escape from arrest. That suspect, the law continues, must have committed or attempted to commit a forcible felony and pose a danger to human life.

The killing of Rose spurred multiple protests over the summer. The week after it occurred, District Attorney Stephen A. Zappala Jr.’s office filed a single homicide count against Rosfeld, of Verona, who turns 31 on Sunday. A verdict could bring new disturbances, and local law enforcement and businesses have been planning for that possibility for weeks.

Both the jury selection — held in Dauphin County because of the case’s publicity — and the trial moved along briskly. Over 2½ days, county Chief Trial Deputy District Attorney Dan Fitzsimmons and Assistant District Attorney Jonathan Fodi put on 21 witnesses. On Thursday afternoon and into Friday morning, defense attorney Patrick Thomassey presented just two: Rosfeld, and a use-of-force expert.

Common Pleas Judge Alexander P. Bicket presided. Early Friday, the jury composition shifted when one white woman was dismissed from service and a white man moved from the alternate pool to the panel that went into deliberations. The final 12-member jury — seven men and five women, including three black jurors -— began its deliberations early Friday evening.

After the prosecution closed, Thomassey filed a motion for acquittal, contending that the prosecution had failed to show evidence of malice. “We have a police officer who is doing his duty,” he said. “It’s not the hardness of heart and the wickedness that’s required for first-degree or third-degree murder. It’s just not. He is doing his duty.” Bicket, though, denied the motion.

Thomassey them presented Rosfeld — an unusual move in a murder trial. For just under an hour and a half, the former officer told the jury that he thought Antwon or Hester had pointed a weapon at him. “I did it to protect myself and the community,” he said. Why three shots? Rosfeld said he has been “trained to fire until the threat is eliminated.” But when he saw “the threat” lying on the ground, wounded, trying to breathe, he said, “I was upset, shocked.”

The defense’s use-of-force expert, former state trooper Clifford Jobe, said he couldn’t find fault in Rosfeld’s handling of the encounter.

In their closings Friday afternoon, the attorneys chose very different pieces of evidence on which to focus. Thomassey zoomed in on the drive-by shooting that preceded the encounter between Rosfeld and Rose, and their reaction to being pulled over. “Mr. Rosfeld didn’t wake up that day and decide to shoot someone,” but Antwon Rose II and Zaijuan Hester did, he told the jury. “If Rose and Hester did nothing wrong, why did they run?” he asked jurors. “You and I wouldn’t do that.” Then he answered his own question. “They knew what they did, and they wanted to get away.”

He sought to cast doubt on the video evidence in the case, emphasizing that the videos were recorded by witnesses who were some distance from the scene. Rosfeld, by contrast, was about eight yards away from Antwon when he fired, the defense attorney said. At one point, he stood a few feet from the jury and lifted a gun that had been used as evidence in the case, pointing it at the wall beside the jury. “About that far,” he said over the weapon. “About eight yards. Who had a better view of what was happening?”

Prosecutor Jonathan Fodi countered in closing that Mr. Rosfeld could not have reasonably felt threatened by Antwon. “Every single time the defendant pulled the trigger and pointed it at Antwon Rose’s body, he had the intent to kill. Every one of them is backward to frontward. Every one of them at a time when Antwon Rose posed no risk to Michael Rosfeld,” the prosecutor said. “When an officer fails to wait for backup; fails to give commands; when they deceive us; when they point a deadly weapon at a 17-year-old running away, that rises to the level of murder,” he said.

Staff writer Liz Navratil contributed to this article.