A former Minneapolis police officer charged in connection with the murder of George Floyd pleaded guilty on Monday as his trial was about to begin, a court spokesperson confirmed.

J Alexander Kueng, who pleaded guilty to one count of aiding and abetting manslaughter in state court, was one of three officers who did not intervene while Derek Chauvin, a white policeman, knelt on Floyd’s neck for more than nine minutes in May 2020, killing him.

Kueng and Thomas Lane helped Chauvin restrain Floyd, an unarmed black man, while another officer, Tou Thao, kept bystanders from approaching the scene.

All three were previously convicted in federal court of depriving Floyd of his civil rights and sentenced in July to between 2-1/2 and 3-1/2 years in prison. Chauvin was convicted of murder in a state trial and sentenced to 22-1/2 years; he also pleaded guilty to related federal charges and is serving a federal sentence of 21 years concurrently.

Floyd’s death sparked months of nationwide protests over police brutality.

Kueng’s plea agreement includes a sentence of 3-1/2 years that will be served concurrently with his federal sentence, according to Matt Lehman, a spokesperson for Hennepin County District Court. Lane accepted a similar plea deal in May.

Kueng’s defense attorney and the Minnesota attorney general’s office, which is prosecuting the case, did not immediately respond to requests for comment.

Thao, who rejected a comparable agreement in August, decided on Monday to waive his right to a jury trial, according to the Star Tribune newspaper. Instead, Thao agreed to have a state judge determine his guilt based on evidence submitted jointly by prosecutors and the defense, the newspaper reported.