In a plea deal with federal prosecutors, former South Carolina police officer Michael Slager admitted Tuesday to using excessive force in the shooting death of Walter Scott.

Slager shot Scott in the back as the unarmed man was running away from Slager after a traffic stop in April 2015. In a reversal from his previous account of events, Slager admitted in court Tuesday that he did not shoot Scott in self-defense and said that his use of force was unreasonable.

Slager pleaded guilty in US District Court in South Carolina to a federal charge of deprivation of rights under the color of law. In exchange for the plea, state murder charges, as well as two other federal charges, will be dismissed.

Slager faces a maximum penalty of life in prison when he is sentenced later this year, CNN reports.