PITTSBURGH—The former major in charge of guards at the Allegheny County Jail pleaded guilty to falsifying a report as part of a cover up in which he denied beating an inmate who was caught trying to escape through the jail ventilation system.

James Donis, 50, pleaded guilty Monday and was allowed to remain free bond until he returns for sentencing Feb. 20 under federal guidelines that suggest he receive between 12 and 18 months in prison.

The falsifying documents charge was the most serious of three Donis faced and carries a maximum of 20 years in prison. Donis' guideline range is far less because he has no criminal record.

Donis also acknowledged violating the civil rights of inmate Gary Barbour Jr. by punching him, and of making a false statement to the FBI, which investigated the claims. Barbour also has filed a federal civil rights lawsuit against Donis, the county and several other guards who allegedly participated in beating him after his ill-fated escape attempt on April 6, 2010.

Although the criminal civil rights and false statements charges have been dismissed, Senior U.S. District Judge Gustave Diamond can take those allegations into account for sentencing purposes.

Donis and his criminal defense attorney, Charles Porter Jr., declined comment after the guilty plea, as did Assistant U.S. Attorney Shaun Sweeney.

Earlier this month, a federal magistrate rejected motions to dismiss Barbour's lawsuit. Donis' attorney in the lawsuit declined to comment on how his guilty plea might affect that litigation. Attorneys representing other guards and the county in the lawsuit did not immediately respond to a request for comment Monday.

But U.S. Magistrate Judge Lisa Lenihan's 15-page ruling earlier this month allowing Barbour's lawsuit to go forward sheds more light on his claims.

On Monday, Donis simply acknowledged punching Barbour several times and with fabricating an addendum to his report claiming that he hit the inmate only because he was "combative, attempted to break free, and refused to follow orders." Donis acknowledged that Barbour didn't resist after he was caught in the air duct.

But documents filed in the lawsuit show Barbour claims one guard kicked him in the back so hard that Barbour soiled himself, before Donis and several other guards punched him as punishment for trying to escape.

"After allegedly putting on leather gloves and stating, 'I'm your worst nightmare,' Donis began striking Plaintiff in the face," Lenihan said in her ruling, paraphrasing Barbour's claims.

Barbour's lawsuit was filed in October 2011 and alleges he was wrongly kept in psychological segregation as a way to keep him from having writing materials which, he alleges, was done to keep him from filing a lawsuit or other formal complaint about the beating.

Donis had 22 years' experience at the jail before he was fired from his $69,000-a-year job three weeks after the lawsuit was filed.

Barbour still is serving a 15- to 30-month prison sentence for his attempted escape and wasn't in court when Donis pleaded guilty.

But Barbour's civil attorney, Ronald Barber, was there and said the guilty plea should help the lawsuit because Donis acknowledged doing what Barbour has always claimed.

"I think that will be just as useful as anything in my case," Barber said.