Tou Thao, as he stood between concerned bystanders as George Floyd was being killed on May 25, 2020, by fellow police officers. (Image from video provided by Darnella Frazier/The Minnesota Star Tribune)

Tou Thao, the ex-Minneapolis police officer who nearly three years ago kept back concerned bystanders as George Floyd died under the knee of convicted cop Derek Chauvin, was found guilty Tuesday of aiding and abetting manslaughter.

The verdict by Hennepin County District Judge Peter Cahill came in the last case to be prosecuted in either state or federal court in the trials of the four officers who had roles in the killing at 38th Street and S. Chicago Avenue on May 25, 2020. Floyd's death was decried globally as an especially brazen act of police brutality.

"Thao, Chauvin's partner on that night, was an experienced Minneapolis police officer with almost a decade's experience. He knew that the officers' prone restraint could kill," Cahill wrote. "Like the other officers, Thao had been trained specifically to turn an individual onto his side to avoid positional asphyxia, the very thing that several eminent medical specialists who testified at trial concluded caused Floyd's death.

"Like the bystanders, Thao could see Floyd's life slowly ebbing away as the restraint continued. Yet Thao made a conscious decision to actively participate in Floyd's death: He held back the concerned bystanders and even prevented an off-duty Minneapolis firefighter from rendering the medical aid Floyd so desperately needed."

Thao asked for a bench trial, letting the judge determine his guilt or innocence rather than a jury. The prosecution and defense agreed on stipulated evidence from the previous state trial of Chauvin and the federal civil rights trial of Thao and ex-officers Thomas Lane and J. Alexander Kueng, who also were convicted in Floyd's death. Thao remains in custody ahead of sentencing, scheduled for Aug. 7.

Robert Paule, Thao's attorney, said he plans to appeal the verdict. "I respectfully disagree with the decision, and I think it expands the doctrine of aiding and abetting beyond what we've seen [defined] at the appellate level."

Paule said his client was "disappointed. He really is."

Thao has long insisted that he was largely unaware of the deadly peril of what was going on a few feet behind him as he stood between a dying Floyd and the increasingly worried and vocal crowd gathered at the curb.

In his verdict, Cahill cast doubt on how, in his federal testimony, Thao described himself as merely a "human traffic cone" between the officers who pinned Floyd to the ground and the bystanders, noting that he "directly interacted with Chauvin, Kueng and Lane and advised them on their restraint, indicating he was aware of their actions."

The judge also pointed out that Thao missed an opportunity to save Floyd's life that night when he retrieved from one of the squad cars a "hobble" — a device that restrains a suspect by their hands and feet. Thao told the officers to "hold on" and instead continue to keep Floyd pinned to the pavement.

"Thao's stated reason? 'If we hobble him, the sergeant is going to have come out' to complete paperwork for a use-of-force review mandated by MPD policy whenever the hobble device was deployed." Cahill wrote. "The short of it: Tou Thao did not want to follow the proper protocol and the work it would entail. George Floyd died as a result."

Attorney General Keith Ellison, whose office led the prosecution of the four fired officers, said in a statement Tuesday that "the conviction of Tou Thao is historic and the right outcome. It brings one more measure of accountability in the tragic death of George Floyd. Accountability is not justice, but it is a step on the road to justice."

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

Attorneys for Floyd's survivors, led by Benjamin Crump, said in a statement that the family "is grateful for 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."

Cahill's 177-page finding of guilt, which includes an exhaustive recounting of the trial, cast aside any notion that Thao was largely oblivious to Floyd nearing his final breath because of the other officers' actions.

"Thao actively encouraged his three colleagues' dangerous prone restraint of Floyd while holding back a crowd of concerned bystanders begging the officers to render medical aid," the judge wrote. "Thao knew, as the minutes passed and the restraint continued unimpeded, that Floyd had stopped talking and fallen silent, had stopped moving altogether, and had become totally unresponsive. In fact, by about six minutes into the restraint, Floyd stopped breathing, lost consciousness and became pulseless."

Thao's sentence could range from three to five years. He has remained in segregated custody in the Hennepin County jail since October, when a joint trial with Kueng was expected to begin. In an 11th-hour resolution, Kueng pleaded guilty and Thao waived his right to a jury trial, leaving the verdict to Cahill.

The joint trial had been expected to last until mid-December and involve dozens of witnesses.

Kueng and fellow officer Thomas Lane helped Chauvin hold a handcuffed Floyd on the ground while Thao held back bystanders. Chauvin's knee pinned Floyd's neck for more than 9 minutes.

Among the group was Darnella Frazier, a teenager who lived nearby and whose video of the event proved pivotal for prosecutors and shocked millions around the world.

"The world needed to see what I was seeing," Frazier told the Star Tribune the next day. "Stuff like this happens in silence too many times."

Chauvin was tried before a worldwide audience, that watched the proceedings on livestream, and convicted of second-degree murder and manslaughter in 2021. He also pleaded guilty to federal charges for violating Floyd's civil rights and is serving a 20-year sentence.

Kueng, Thao and Lane were found guilty of federal charges in a jury trial and are serving federal sentences ranging from 2½ to 3½ years.

Lane was sentenced in September to three years in prison after he pleaded guilty in May to aiding and abetting second-degree manslaughter. Kueng in October admitted to the same charge and was sentenced to 3¹⁄₂ years. Both will serve their sentences concurrently with their federal sentences.

At his federal sentencing in July when he received 3½ years, Thao heavily quoted scripture in a 23-minute statement that spoke of retribution, describing the case as corrupt and saying the legal process caused him "great distress."