A white Cleveland patrolman who fired down through the windshield of a suspect's car at the end of a 137-shot barrage by police that left the two unarmed black occupants dead was acquitted Saturday of criminal charges by a judge who said he could not determine the officer alone fired the fatal shots.Michael Brelo, 31, put his head in hands as the judge issued a verdict that prompted an angry response outside the courthouse.The acquittal came at a time of nationwide tension among police and black citizens punctuated by protests over deaths of black suspects at the hands of white officers and following a determination by the U.S. Department of Justice that city police had a history of using excessive force and violating civil rights.Before issuing his verdict, Cuyahoga County Common Pleas Judge John P. O'Donnell noted the recent unrest in Ferguson, Missouri, and Baltimore over the deaths of black suspects but said he would not "sacrifice" Brelo to an angry public if the evidence did not merit a conviction."Guilty or not guilty, the verdict should be no cause for a civilized society to celebrate or riot," he said.Brelo who fired a total of 49 shots, including 15 down through the windshield while standing on the hood of the suspects' vehicle faced as many as 22 years in prison had the judge convicted him on two counts of voluntary manslaughter for his role in the end of a Nov. 29, 2012 chase that began after Timothy Russell's car backfired as he sped past Cleveland police headquarters. Police officers and bystanders thought someone inside the vehicle had fired a gun.His sister, Michelle Russell, said she believed Brelo would ultimately face justice, despite the judge's decision."He's not going to dodge this just because he was acquitted," she said. "God will have the final say."The officers who surrounded the car were angry that the pair didn't pull over and didn't give them a chance to surrender, she said.Michelle Russell urged protesters to be peaceful and work for real solutions."We need to organize and figure out a way to stop this from happening again," she said.Community and city leaders braced for the possibility of unrest in response to the verdict, which came as investigators work toward making a decision on whether charges will be filed in the death of a black 12-year-old boy carrying a pellet gun who was shot by a white rookie officer late last year in a Cleveland park.One activist, Carol Steiner, said the verdict is "a very bad precedent for Cleveland" with a decision still to come in the death of the 12-year-old, Tamir Rice. "Police murder people of color and not have to serve one day in jail."The U.S. Justice Department, U.S. Attorney's Office and the FBI will begin reviewing the testimony and evidence and review all available legal options, said Vanita Gupta, head of the Justice Department's Civil Rights Division.After the verdict, about 30 sheriff's deputies stood in front of the courthouse bearing clear shields as protesters with bullhorns chanted. The deputies then moved inside the entrance of the justice center, and the plaza in front of the building was soon cordoned off.Brelo waived his right to a jury trial, opting instead to let the judge decide the case after hearing the evidence.O'Donnell spent nearly an hour summing up his conclusion, an involved explanation that included mannequins marked with the gunshot wounds that the two motorists suffered .O'Donnell said that while Brelo likely fired fatal shots in the final seconds of the encounter in a school parking lot, other officers fired fatal shots as well. Brelo could have been convicted of lesser charges of felonious assault, but O'Donnell determined his actions were justified in shooting, which included reports of shots being fired from the beat-up Chevy Malibu that Russell was driving, because they perceived a threat.Brelo's lead attorney, Patrick D'Angelo, told reporters after the verdict his team was "humbled by the verdict but not emboldened by it.""Officer Brelo risked his life on that night," D'Angelo said, only to be attacked by prosecutors."I've never in my 37 years witnessed such a vicious and unprofessional prosecution of a police officer," he said.Cuyahoga County prosecutor Tim McGinty said he respects the judge's decision and urged others to do so, as well.Zach Reed, a councilman who represents a black area of southeast Cleveland, said he thought Brelo should have been guilty of felonious assault. "We may not agree with the decision but we will not pillage, loot and burn the city as a result of this verdict," he said.Thirteen officers fired at a car with Russell and Malissa Williams inside after a 22-mile (35-kilometer)-long chase that saw speeds reach 100 mph (160 kph). More than 100 police officers in 62 marked and unmarked cars got involved in the pursuit.Only Brelo was charged criminally because prosecutors said he waited until the car had stopped and the pair no longer posed a threat to fire his final 15 shots.Russell, 43, and Williams, 30, were each shot more than 20 times. While prosecutors argued they were alive until Brelo's final salvo, medical examiners for both sides testified that they could not determine the order in which the fatal shots were fired.Brelo has been on unpaid leave since he was indicted May 30, 2014.Authorities never learned why Russell didn't stop. He had a criminal record including convictions for receiving stolen property and robbery and had been involved in a previous police pursuit. Williams had convictions for drug-related charges and attempted abduction. Both were described as mentally ill, homeless and addicted to drugs. A crack pipe was found in the car.In addition to the charges against Brelo, a grand jury charged five police supervisors with misdemeanor dereliction of duty for failing to control the chase. All five have pleaded not guilty and no trial date has been set.The shooting helped prompt a months-long investigation by the U.S. Department of Justice, which concluded last December that the Cleveland police department had engaged in a pattern and practice of using excessive force and violating people's civil rights. The city and DOJ are currently negotiating a reform-minded consent decree that a federal judge will approve and independent monitors will oversee.