A D.C. man pleaded guilty Friday to the killing of a 56-year-old man in 2007, authorities said.

Ronnell James, 39, pleaded guilty in D.C. Superior Court to second-degree murder while armed in the April 7, 2007, slaying of Robert Beidleman in his Northeast Washington apartment, according to the U.S. attorney’s office.

Authorities said Beidleman was found bound, gagged and fatally stabbed. James was arrested in November 2008.

James is scheduled to be sentenced April 13. He faces a maximum sentence of life in prison without parole.

According to authorities, James told police he had another person’s help in the crime. Nobody else has been arrested.

Read more: The Post’s crime coverage