WASHINGTON D.C.: A South Carolina policeman who was filmed shooting an unarmed black man in the back after a traffic stop pleaded guilty Tuesday to unlawful killing while performing official duties, which could bring up to life in prison. The Justice Department said that former North Charleston, South Carolina, police officer Michael Slager, 35, agreed to the single federal charge five months after a jury failed to convict him of murder in the case. Slager’s plea will resolve both the federal and state cases against him over the shooting two years ago, which came amid a spate of police shootings of unarmed black men that sparked widespread anger and protests. In December, a lone jury member in the state case prevented a murder conviction, forcing the judge to declare a mistrial and plan for a new trial. “The Department of Justice will hold accountable any law enforcement officer who violates the civil rights of our citizens by using excessive force,” said Attorney General Jeff Sessions. “Such failures of duty not only harm the individual victims of these crimes; they harm our country, by eroding trust in law enforcement and undermining the good work of the vast majority of honorable and honest police officers.” Slager, who is white, pulled Walter Scott over for a broken brake light in North Charleston on April 4, 2015.