Ohio grand jury probing black man's death in police traffic stop
Crime scene (Shutterstock)

A grand jury was seated in Cincinnati on Thursday as prosecutors mull bringing charges against a white university police officer who fatally shot an unarmed black man during a traffic stop over the weekend.

University of Cincinnati police officer Ray Tensing shot and killed Samuel Dubose, 43, on Sunday evening after pulling him over near the school because his car lacked a license plate, police and city officials said.

The grand jury began hearing "preliminary information" on the case on Thursday, said Julie Wilson, spokeswoman for the Hamilton County Prosecutor's Office, as protesters continued to call for the release of video from Tensing's body camera.

Prosecutor Joe Deters has denied requests to release the video until the investigation concludes, which could happen by the end of next week.

"It should be clear why we are not releasing the video only a few days after the incident occurred," Deters said. "The Grand Jury has not seen the video yet and we do not want to taint the Grand Jury process.  The video will be released at some point, just not right now."

Cincinnati Mayor John Cranley on Wednesday questioned how the traffic stop escalated so quickly.

"A pullover related to a license plate should not, in the normal course of events, lead to lethal force and a death as it has in this case," Cranley told reporters.

A series of police killings of unarmed black men in U.S. cities including New York, Baltimore and Ferguson, Missouri, over the past year has sparked waves of protest and a fresh debate over race, the justice system and the use of force by law enforcement officers.

Meanwhile, officials are investigating the recent death in a Texas jail of Sandra Bland, a black woman pulled over for a minor traffic violation, as a possible murder, even though it was originally ruled a suicide.