WASHINGTON (CNN) -- A Chicago, Illinois, police officer who was videotaped beating a man restrained in a wheelchair at a hospital emergency room pleaded guilty Thursday to using "excessive or unreasonable force" against the victim, Justice Department officials announced.

Veteran police officer William Cozzi, 51, entered his plea in a federal court in Chicago more than three years after the beating of Randle Miles.

A plea agreement filed with the court said the victim -- who was taken to Norwegian American Hospital after being stabbed on August 2, 2005 -- had been loud and verbally abusive, so Cozzi handcuffed and shackled the man.

Cozzi said that although the victim posed no physical threat, the officer repeatedly "used a 'sap,' a dangerous weapon, to strike [the victim] in the face and body."

He also admitted he prepared a false arrest report stating Miles had tried to punch him, but omitting that Cozzi had struck Miles.

The officer was indicted on the civil rights charge last April. He will be sentenced March 26 before U.S. District Judge Blanche Manning.

Cozzi could be sentenced to a maximum of 10 years in prison and fined up to $250,000. The plea agreement says prosecutors will argue that according to nonbinding guidelines, the sentence should be about seven years, while defense attorneys may argue for a lighter sentence.