The former South Carolina police officer who shot and killed Walter Scott, an unarmed black man, following a traffic stop was sentenced Thursday to 20 years behind bars in a federal case stemming from the fatal encounter.

Michael Slager, who had been an officer with the North Charleston police, was charged with murder in state court and indicted on federal civil rights charges after the shooting in 2015. His murder trial ended with a deadlocked jury last year, and prosecutors had vowed to retry Slager in state court.