(CNN) -- With the acquittal of an East Pittsburgh police officer in the fatal shooting of 17-year-old Antwon Rose II, the teen's family attorney said their fight for justice is far from over.
"It will have to be challenged, in the Supreme Court of Pennsylvania. It will have to continue to be challenged on a federal level," attorney S. Lee Merritt said Friday.
"Antwon Rose was shot in his back. ... He was unarmed, and he did not pose a threat to the officer or to the community, and the verdict today says that is OK, that is acceptable behavior from a police officer," he said.
Rose was shot three times when he ran during a traffic stop on June 19. A witness to the shooting captured it on video that was posted on Facebook.
Officer Michael Rosfeld, 30, faced a criminal homicide charge that included murder, voluntary manslaughter and involuntary manslaughter under Pennsylvania law. If convicted, he could have been sentenced to life in prison. He was found not guilty on all counts Friday.
The shooting raised racial tensions. Rosfeld is white, and Rose was black.
Four hours of jury deliberations
Three and a half days of testimony and four hours of jury deliberations led to a verdict of not guilty on all counts.
Rosfeld said in testimony Thursday that he initially pulled over the gold Chevrolet Cruze that Rose and others were in because it matched the description of a car involved in a drive-by shooting 20 minutes earlier. He testified that he knew from radio dispatch communications that between 10 and 12 shots were fired in the drive-by, which he said signaled to him that there may have been more than one armed suspect in the car.
The car with a shattered rear windshield was riddled with bullet holes when Rosfeld called in a felony traffic stop.
Rosfeld said he saw both Rose and the other passenger, Zaijuan Hester, then 17, move from the car at the same time. He acknowledged that he couldn't differentiate between the two to say which one was pointing what he thought was a handgun at him, so he fired his gun in the general direction of both.
"I'm not going to wait to be attacked," Rosfeld said on the stand when pressed by prosecutor Dan Fitzsimmons on why he didn't wait in his police vehicle until other officers arrived.
Rosfeld initially told police his intention had been to get all three occupants on the ground as he awaited backup, according to the criminal complaint.
Protests begin immediately
Demonstrators gathered outside the courthouse as soon as the verdict came in. The June shooting sparked protests as crowds questioned the police department's use of deadly force against an unarmed youth.
Pittsburgh Mayor William Peduto said in a statement following the not guilty verdict that he grieves with Rose's loved ones and the community.
"Words cannot heal the pain so many are feeling," Peduto said. "Only action can begin the process, a process that will take work and understanding. An understanding that inequality exists and we have a moral obligation to address it."
Rosfeld had been on the job for two weeks
Rosfeld testified that he'd been sworn in nearly an hour before the shooting. He'd been working on the job for about two weeks then and had been a police officer in other jurisdictions since 2011.
Rosfeld said he ordered the driver to the ground and Rose, the front seat passenger, left the car and turned his hand toward Rosfeld, and the officer said he saw something dark he perceived as a gun.
He has been criticized for an inconsistency in his telling of the incident, because when asked again to recount the events, Rosfeld "told the detectives that he did not see a gun when the passenger emerged and ran. When confronted with this inconsistency, Rosfeld stated he saw something in the passenger's hand but was not sure what it was," the complaint said.
Police later found two stolen guns in the car, traces of gun residue on Rose's hand and the empty clip of a handgun in his pants pocket, according to court records.
Witnesses during the trial testified that Rosfeld was distraught and emotional after realizing he fatally shot Rose.