PITTSBURGH (AP) -- The father of a slain black teenager pleaded for peace Saturday after the acquittal of a white police officer triggered an apparent retaliatory shooting at the defense attorney's office and touched off protests in the streets of Pittsburgh.
Police put officers on 12-hour shifts until further notice.
The verdict late Friday in the deadly shooting of 17-year-old Antwon Rose II angered his family and civic leaders and prompted hundreds of people to gather Saturday afternoon at an intersection called Freedom Corner in the Hill District neighborhood, the historic center of black cultural life in Pittsburgh. One man held a sign with the names of black men killed by police around the U.S.
"It's very painful to see what happened, to sit there and deal with it," Rose's father, Antwon Rose Sr., told the crowd. "I just don't want it to happen to our city no more."
Afterward, he told reporters: "I want peace, period, all the way around. ... Just because there was violence doesn't mean that we counter that with violence."
The mostly white crowd then marched through downtown Pittsburgh and other city neighborhoods, periodically blocking streets as they chanted, "Who did this? Police did this!" The protest soon moved onto the University of Pittsburgh campus. Police reported no immediate arrests or injuries.
Early Saturday, five to eight shots were fired into the building where the officer's attorney, Patrick Thomassey, works, police in nearby Monroeville said. No one was hurt. Police said they had been staking out the place as a precaution, and the gunfire erupted after they left to answer another call around midnight.
Former East Pittsburgh police Officer Michael Rosfeld had been charged with homicide for shooting Rose as the unarmed teenager ran away from a traffic stop in June. Rosfeld testified that he thought Rose or another suspect had a gun pointed at him and that he fired to protect himself and the community.
"I hope that man never sleeps at night," Rose's mother, Michelle Kenney, said of Rosfeld after the verdict, according to the Pittsburgh Post-Gazette. "I hope he gets as much sleep as I do, which is none."
Rose's family is now pressing ahead with a federal civil rights lawsuit filed against Rosfeld and East Pittsburgh, a small municipality about 10 miles (16 kilometers) from downtown Pittsburgh, where the trial was held.
Attorney S. Lee Merritt, who represents Rose's mother in the litigation, said the verdict was based on Pennsylvania law regarding the use of force that he considers unconstitutional.
"The protest is an appropriate response to injustice," Merritt said, adding that he believes the state law is why jurors reached their verdict of acquittal.
He also called the shots at Rosfeld's attorney's office "an act of cowardice and barbarism that does nothing but perpetuate the stereotypes often used to justify police brutality."
Thomassey told reporters after the verdict that Rosfeld is "a good man, he is." The defense attorney said he hopes the city remains calm and "everybody takes a deep breath and gets on with their lives."
The leaders of two major Pittsburgh charities issued a statement expressing "shock and outrage" over the verdict.
"Pittsburgh now sadly joins a disturbing and ever-growing catalogue of cases across the United States where law enforcement or security officials have walked free after the killings of young black men under questionable circumstances," wrote Maxwell King, president and CEO of the Pittsburgh Foundation, and Grant Oliphant, president of the Heinz Endowments.
"We have asked the question, 'Would Antwon Rose be alive today if he had been white?' We, his family and African American community leaders believe that more than likely he would be."
Pittsburgh was in the spotlight less than five months ago, when a gunman ranting about Jews killed 11 people at a synagogue.
Rose was riding in an unlicensed taxi that had been involved in a drive-by shooting minutes earlier when Rosfeld pulled the car over and shot the teenager in the back, arm and side of the face. Neither Rose nor another teen in the taxi was holding a weapon when the officer opened fire, though two guns were later found in the vehicle.
Rosfeld had worked for the East Pittsburgh Police Department for only a few weeks and was sworn in just hours before the shooting.
The 12-person jury -- including three black members -- saw video of the fatal confrontation. The jury took less than four hours to reach a verdict.
Prosecutor Jonathan Fodi argued that the video showed there was no threat to the officer. But a defense expert testified Rosfeld was within his rights to use deadly force to stop suspects he thought had been involved in a shooting.
The prosecution did not call its own use-of-force expert, a decision the American Civil Liberties Union of Pennsylvania questioned. But Mike Manko, a spokesman for the district attorney's office, said prosecutors were confident they had what they needed to make their case.
Shortly before the traffic stop, another person in the taxi, Zaijuan Hester, rolled down a window and shot at two men on the street, hitting one in the abdomen. Hester, 18, pleaded guilty last week to aggravated assault and firearms violations. He said he, not Rose, did the shooting.
Prosecutors had charged Rosfeld with an open count of homicide, meaning the jury had the option of convicting him of murder or manslaughter.