Former U.S. police officer Derek Chauvin has pleaded guilty to violating George Floyd's civil rights. The federal charges were brought by the Justice Department in May, several weeks after Chauvin was convicted for murder and manslaughter in the killing of Floyd. Chauvin, 45, is serving a sentence of 22.5 years. A federal prosecutor said he would ask a judge to extend it to 25 years. The killing ignited one of the largest protest movements across the U.S.