RALEIGH, N.C. — North Carolina state prosecutors announced Friday that they won’t retry a white police officer who fatally shot an unarmed black man, saying that talking with jurors after the mistrial helped convince them they cannot get a conviction.

The jury deadlocked 8-4 last week in favor of acquitting Charlotte-Mecklenburg Officer Randall Kerrick, leading the judge to declare a mistrial. Kerrick was charged with voluntary manslaughter in the September 2013 death of Jonathan Ferrell, a former college football player.

“In consideration of the jurors’ comments, the evidence available to the state, and our background in criminal trials, it is our prosecutors’ unanimous belief a retrial will not yield a different result,” Senior Deputy Attorney General Robert Montgomery told the Mecklenburg County district attorney.

Police said Ferrell wrecked his car on the morning of Sept. 14, 2013, and went to a nearby house and banged on the door, apparently seeking help. The resident called police, and three officers, including Kerrick, responded.

Investigators said one deployed his Taser without apparent effect on Ferrell before Kerrick fired 12 shots, 10 of which hit him.

Kerrick testified that he repeatedly fired because Ferrell kept charging at him and that he didn’t think his weapon was even working.

Prosecutors said nonlethal force should have been used to subdue Ferrell, who played football at Florida A&M University. The two officers with Kerrick didn’t fire their guns.

After three weeks of testimony and four days of deliberations, the jury couldn’t overcome its deadlock.

“Our prosecutors believe they were able to introduce the relevant evidence and examine the witnesses, including the defendant, appropriately and that the jury fully considered the details of the case,” Montgomery wrote. “However, meeting the standard of proof of beyond a reasonable doubt could not be achieved.”

The Ferrell family has settled a lawsuit with the city of Charlotte, receiving $2.25 million. Chris Chestnut, the attorney for the Ferrell family, wasn’t immediately available for comment, but Ferrell’s mother said that she doesn’t think prosecutors tried hard enough to convict Kerrick.

“They didn’t try hard enough. It was just another black life,” Georgia Ferrell said. “They don’t care.”

She said two prosecutors called her Friday morning to tell her that the case would not be retried.

“I am going to continue to fight,” she said. She already planned to use part of the civil settlement for a foundation named for her son. “I am going to work on the foundation, continue to work for justice. It’s not the end.”

Kerrick has been free on bond. He is suspended without pay from the Charlotte-Mecklenburg Police Department.

On Friday, Charlotte-Mecklenburg police Chief Kerry Putney said internal affairs will conduct an investigation to determine if Kerrick “followed all department policies and procedures” in the shooting.

Kerrick’s attorney George Laughrun said his client is relieved there will not be another trial, but there wasn’t necessarily a reason to celebrate.

“I think there are no winners or losers here, obviously,” Laughrun said.

Jibril Hough, a spokesman for the Islamic Center of Charlotte and an activist on behalf of the Ferrell family, called the attorney general’s decision “heartbreaking news.” Hough said he had been on a conference call Thursday night with Ferrell’s relatives to discuss efforts to convince the attorney general’s office to retry the case.

“Two years later, Jonathan Ferrell is still looking for help,” Hough said, “and just like that September night after he wrecked his car, doors are being closed and people are refusing to give him the help he needs.”

It took two grand juries to indict Kerrick. The first refused to do so, suggesting prosecutors seek a lesser charge. But Attorney General Roy Cooper’s office tried again. The 14-4 vote by jurors to indict met the minimum needed to charge the officer.

Speaking to reporters in Raleigh, Cooper wouldn’t second-guess his special prosecutors, saying they put on a compelling case and that the manslaughter charge was appropriate based on the evidence.

Cooper said the shooting shows the need for better and consistent training of law enforcement officers and pushed for pending legislation to help with it. Putney this week said agency training is being changed and will focus more on how to subdue a suspect.

“The loss of Jonathan Ferrell’s life is a tragedy. It should not have happened,” Cooper said.

The Aug. 21 mistrial led to protests, as some demonstrators lay in the middle of the street soon after the trial ended. Dozens gathered that evening near Charlotte’s minor league baseball stadium as a game was in progress, and later some protesters walked through the city and shouted. Police officers stopped the protesters at one point from entering a covered transit center.

“I understand the frustration,” Cooper said. “Our prosecutors were frustrated, but I think it’s important that we listen to the jury.”