A University of Cincinnati police officer was indicted on Wednesday on murder charges in the fatal shooting last week of an unarmed black motorist who was stopped because of a missing front license plate. Hamilton County prosecutor Joseph Deters called the July 19 killing of Samuel Dubose, 43, "senseless" and "totally unwarranted." Ray Tensing, the 25-year-old white officer who shot Dubose in the head, "wasn't dealing with someone who was wanted for murder," Deters told a news conference. "He was dealing with someone who didn't have a front license plate. This is, in the vernacular, a pretty chicken crap stop." The incident was the latest in a series of fatal confrontations between law enforcement and unarmed individuals across the United States that have raised questions about the use of deadly force by police, especially against minorities, Reuters reported. Tensing was to be arraigned at 10 a.m. EDT on Thursday in the Hamilton County Court of Common Pleas and could be sentenced to life in prison if convicted. Cincinnati officials braced for possible unrest after the grand jury's decision was announced, and the university closed down for the day as a precaution. A racially mixed crowd of about 300 people braved a heavy rain Wednesday evening to attend a peaceful "Black Lives Matter" rally outside the courthouse, where relatives of Dubose and supporters welcomed the indictment but called for punishment of other officers involved in the incident. Several dozen protesters peeled off from the rally and marched to police headquarters, some chanting, "This is what democracy looks like," but there were no immediate reports of any trouble. A body-camera video that Deters played for reporters showed how the traffic stop of Dubose escalated into deadly violence. After failing to provide a driver's license at Tensing's request, Dubose tried to prevent Tensing from opening the car door as the officer ordered him to remove his seat belt. The car started slowly rolling forward as Tensing reached in and yelled for him to stop. The officer then pulled his gun and fired once, killing Dubose.