LOUISVILLE, Ky. (AP) — A federal judge declared a mistrial Thursday afternoon after a jury deadlocked on civil rights charges against a former Louisville police officer who fired stray bullets in the deadly raid that left Breonna Taylor dead.

Brett Hankison was charged with using excessive force that violated the rights of Breonna Taylor, her boyfriend and her next-door neighbors. Hankison fired 10 shots into Taylor’s window and a glass door after officers came under fire during the flawed drug warrant search on March 13, 2020. Some of his shots flew into a neighboring apartment, but none of them struck anyone.

The 12-member, mostly white jury struggled to reach a verdict over several days. On Thursday afternoon, they sent a note to the judge saying they were at an impasse. U.S. District Judge Rebecca Grady Jennings urged them to keep trying, and they returned to deliberations.

The judge reported that there were “elevated voices” coming from the jury room at times during deliberations this week, and court security officials had to visit the room. Jurors told the judge Thursday they were deadlocked on both counts against Hankison, and could not come to a decision.

The mistrial could result in a retrial of Hankison, but that would be determined by federal prosecutors at a later date.

Hankison, 47, was acquitted by a Kentucky jury last year on wanton endangerment charges. State prosecutors had alleged he illegally put Taylor’s neighbors in danger. Months after his acquittal last year, the U.S. Department of Justice brought the new charges against Hankison, along with a group of other officers involved in crafting the warrant.

U.S. Attorney General Merrick Garland said Taylor, a 26-year-old Black woman studying to be a nurse, “should be alive today” when he announced the federal charges in August 2022. The charges Hankison faced carried a maximum sentence of life in prison.

Hankison was the only officer who fired his weapon the night of the Taylor raid to be criminally charged. Prosecutors determined that two other officers were justified in returning fire after one was shot in the leg.

Federal prosecutor Michael Songer said Monday in the trial’s closing arguments that Hankison “was a law enforcement officer, but he was not above the law.” Songer argued that Hankison couldn’t see a target and knew firing blindly into the building was wrong.

Hankison’s attorney, Stewart Mathews, countered that he was acting quickly to help his fellow officers, who he believed were being “executed” by a gunman shooting from inside Taylor’s apartment. Taylor’s boyfriend had fired a single shot when police burst through the door. Her boyfriend, Kenneth Walker, said he believed an intruder was barging in.

“If his perception was reasonable in the chaos of that moment, that was not criminal,” Mathews said.

The night of the raid, Hankison said he saw the shot from Taylor’s boyfriend in the hallway after her door was breached. He backed up and ran around the corner of the building, firing shots into the side of the apartment.

“I had to react,” he testified. “I had no choice.”