One of three Minneapolis policemen who watched fellow officer Derek Chauvin kill balck man George Floyd by kneeling on his neck pleaded guilty to aiding and abetting manslaughter in the 2020 case.
Chauvin, who is white, was sentenced to 22.5 years in prison last year after his conviction on charges of murdering Floyd, a black man suspected of passing a counterfeit bill.
By entering the plea on Wednesday, former officer Thomas Lane avoided a trial on the more serious charge of aiding and abetting second-degree murder.
Lane agreed to a sentence of three years in prison, the Minneapolis Star Tribune reported. A sentencing hearing has yet to be scheduled.
The two other former officers involved in Floyd's arrest, Tou Thao and J Alexander Kueng, are to face trial in June on both of the state charges, the online Hennepin County Court records said.
"His acknowledgment he did something wrong is an important step toward healing the wounds of the Floyd family, our community and the nation," Minnesota Attorney General Keith Ellison said.
In February, Lane, Thao and Kueng were convicted on federal charges of depriving Floyd of his civil rights by failing to give aid to him when he showed signs of distress.
He was pinned under Chauvin's knee for more than nine minutes.
Chauvin has pleaded guilty in federal court to charges that he violated Floyd's civil rights.
Floyd's killing sparked protests in cities around the world against police brutality and racism.