MINNEAPOLIS >> A former Minneapolis police officer who held back bystanders while his colleagues restrained a dying George Floyd has been convicted of aiding and abetting manslaughter.

Tou Thao, who already had been convicted in federal court of violating Floyd’s civil rights, was the last of four former officers facing judgment in state court in Floyd’s killing. He rejected a plea agreement and, instead of going to trial, let Hennepin County Judge Peter Cahill decide the verdict based on written filings by each side and evidence presented in previous cases.

“There is proof beyond a reasonable doubt that Thao’s actions were objectively unreasonable from the perspective of a reasonable police officer, when viewed under the totality of the circumstances,” Cahill wrote in a 177-page ruling that was filed Monday night and released today.

Floyd, a Black man, died May 25, 2020, after officer Derek Chauvin, who is white, pinned him to the ground with his knee on Floyd’s neck for 9 1/2 minutes as he pleaded for air. The killing, captured on bystander video, touched off protests around the world and prompted a national reckoning with police brutality and racism.

Chauvin, the senior officer at the scene, was convicted of murder and manslaughter in April 2021 and later pleaded guilty in the federal case. Two other officers — J. Alexander Kueng and Thomas Lane — pleaded guilty to state charges of aiding and abetting manslaughter and were convicted with Thao in their federal case.

Minnesota Attorney General Keith Ellison, who led the prosecution team, said Thao’s conviction “brings one more measure of accountability in the tragic death of George Floyd” while calling on Congress to enact a sweeping police overhaul named for Floyd.

“While we have now reached the end of the prosecution of Floyd’s murder, it is not behind us.” Ellison said. “There is much more that prosecutors, law-enforcement leaders, rank-and-file officers, elected officials, and community can do to bring about true justice in law enforcement and true trust and safety in all communities.”

Defense attorney Robert Paule did not immediately return messages seeking comment.

Lawyers for the Floyd family called the verdict “another measure of accountability for his death.”

“Nearly three years after George was killed, the family and Minneapolis community continue to heal as the criminal justice system prevails. With each of these measures of justice, it is even more so demonstrated that police brutality is an illegal — and punishable — act,” civil rights attorney Ben Crump and his team said in a statement.

The judge set sentencing for Aug. 7. Minnesota guidelines recommend four years on the manslaughter count, which Thao would serve concurrently with his 3 1/2-year federal sentence.

Unlike the other three former officers, Thao maintained he did nothing wrong. When he rejected a plea deal in state court last August, he said “it would be lying” to plead guilty.

Cahill based his decision on exhibits and transcripts from Chauvin’s murder trial, which he presided over, and the federal civil rights trial of Thao, Kueng and Lane. Thao was specifically convicted then of depriving Floyd of his right to medical care and of failing to intervene and stop Chauvin. Cahill wrote that he focused on the evidence that pertained to Thao and not on the other officers or their pleas and guilty verdicts.

Thao is Hmong American, Kueng is Black and Lane is white.

Thao testified during his federal trial that he was relying on the other officers to care for Floyd’s medical needs while he served as “a human traffic cone” to control a group of about 15 bystanders and traffic outside a Minneapolis convenience store where Floyd had tried to pass a counterfeit $20 bill.

Thao said that when he and Chauvin arrived, the other officers were struggling with Floyd. He said it was clear to him, as the other officers tried to put Floyd into a squad car, “that he was under the influence of some type of drugs.”

His body camera video showed he told onlookers at one point, “This is why you don’t do drugs, kids.” When an off-duty, out-of-uniform Minneapolis firefighter asked if officers had checked Floyd’s pulse, he ordered her, “Back off!”

Thao acknowledged he heard onlookers becoming more anxious about Floyd’s condition and that he could hear Floyd saying, “I can’t breathe.” But Thao said he didn’t know there was anything seriously wrong with him even as an ambulance took him away.

Cahill wrote that he found that key parts of Thao’s testimony, and his justifications for his actions, were “not credible.”

The judge wrote that under Minneapolis Police Department policies, “it was objectively unreasonable to (among other things): encourage fellow officers to engage in a dangerous prone restraint for 9 minutes and 24 seconds; encourage those officers not to use a hobble; actively assist their restraint by acting as a ‘human traffic cone’; and prevent bystanders from rendering medical aid.”

“Thao’s actions were even more unreasonable in light of the fact that he was under a duty to intervene to stop the other officers’ excessive use of force and was trained to render medical aid,” the judge added.

In keeping with an agreement between the prosecution and defense, Cahill dismissed a more serious aiding and abetting second-degree murder count with a presumptive sentence of 12 1/2 years.

Vice President Kamala Harris and others have called for reviving the George Floyd Justice in Policing Act this year after it stalled in the Senate amid Republican opposition in 2020 and 2021. The legislation aims to eliminate misconduct, racial discrimination and excessive force in policing nationwide. It would ban the use of chokeholds and end the “qualified immunity” that protects officers from lawsuits, among other things.