A Black man was unarmed when Akron police chased him on foot and killed him in a hail of gunfire, but officers believed he had shot at them earlier from a vehicle and feared he was preparing to fire again, authorities said Sunday at a news conference.

Akron police released video of the shooting of Jayland Walker, 25, who was killed June 27 in a pursuit that had started with an attempted traffic stop. The mayor called the shooting "heartbreaking" while asking for patience from the community.

It's not clear how many shots were fired by the eight officers involved, but Walker sustained more than 60 wounds. An attorney for Walker's family said officers kept firing even after he was on the ground.

Officers attempted to stop Walker's car around 12:30 a.m. for unspecified traffic and equipment violations, but less than a minute into a pursuit, the sound of a shot was heard from the car, and a transportation department camera captured what appeared to be a muzzle flash coming from the vehicle, Akron Police Chief Steve Mylett said. That changed the nature of the case from "a routine traffic stop to now a public safety issue," he said.

Police body camera videos show what unfolded after the roughly six-minute pursuit. Several shouting officers with guns drawn approach the slowing car on foot, as it rolls up over a curb and onto a sidewalk. A person wearing a ski mask exits the passenger door and runs toward a parking lot. Police chase him for about 10 seconds before officers fire from multiple directions, in a burst of shots that lasts 6 or 7 seconds.

At least one officer had tried first to use a stun gun, but that was unsuccessful, police said.

Mylett said Walker's actions are hard to distinguish on the video in real time, but a still photo seems to show him "going down to his waist area" and another appears to show him turning toward an officer. He said a third picture "captures a forward motion of his arm."

In a statement shared Sunday with reporters, the local police union said the officers thought there was an immediate threat of serious harm, and that it believes their actions and the number of shots will be found justified in line with their training and protocols. The union said the officers are cooperating with the investigation.

Police said more than 60 wounds were found on Walker's body but further investigation is needed to determine exactly how many rounds the officers fired and how many times Walker was hit.

The footage released by police ends with the officers' gunfire and doesn't show what happened next. Officers provided aid, and one can be heard saying Walker still had a pulse, but he was later pronounced dead, Mylett said.

The chief said an officer firing at someone has to be "ready to explain why they did what they did, they need to be able to articulate what specific threats they were facing ... and they need to be held to account." But he said he is withholding judgment on their actions until they give their statements.

A handgun, a loaded magazine and an apparent wedding ring were found on the seat of the car. A casing consistent with the weapon was later found in the area where officers believed a shot had come from the vehicle.

State Attorney General Dave Yost vowed a "complete, fair and expert investigation" by the Ohio Bureau of Criminal Investigation and cautioned that "body-worn camera footage is just one view of the whole picture."

Akron police are conducting a separate internal investigation about whether the officers violated department rules or policies.

The officers involved in the shooting are on paid administrative leave, which is standard practice in such cases. Seven of them are white, and one is Black, according to the department. Their length of service with Akron police ranges from one-and-a-half to six years, and none of them has a record of discipline, substantiated complaints or fatal shootings, it said.

Demonstrators marched peacefully through the city and gathered in front of the Akron justice center after the video was released. NAACP President Derrick Johnson said in a statement that Walker's death wasn't self-defense, but "was murder. Point blank."

Late Sunday, police in full riot gear fired a dozen tear gas cannisters to disperse a handful of protesters outside the justice center, WKYC-TV reported.

Walker's family is calling for accountability but also for peace, their lawyers said. One of the attorneys, Bobby DiCello, called the burst of police gunfire excessive and unreasonable, and said police handcuffed Walker before trying to provide first aid.

"How it got to this with a pursuit is beyond me," DiCello said.

He said Walker's family doesn't know why he fled from police. Walker was grieving the recent death of his fiancee, but his family had no indication of concern beyond that, and he wasn't a criminal, DiCello said.

"I hope we remember that as Jayland ran across that parking lot, he was unarmed," DiCello said.

He said he doesn't know whether the gold ring found near the gun in the car belonged to Walker.