HONOLULU (AP) — Three former Hawaii prison guards were found guilty of civil rights violations for assaulting an inmate and trying to cover it up, the U.S. Department of Justice said Monday.

A U.S. judge ordered Jason Tagaloa, Craig Pinkney and Jonathan Taum into custody after a jury convicted them last week, the department said.

A fourth former correctional officer, Jordan DeMattos, previously pleaded guilty for his role in the 2015 assault and cover-up, and testified for the government at the three-week trial, federal prosecutors said.

The Hawaii Department of Public Safety fired the men in 2016.

“Justice has been served as those involved were held accountable, Public Safety Director Max Otani said in a statement. “The Department will not tolerate this type of behavior from any employee.”

The guards punched and kicked the inmate while he was lying face-down in a pool of his own blood in the recreation yard at Hawaii Community Correctional Center on the Big Island, prosecutors said.

They later wrote false reports omitting the beating, prosecutors said.

They face up to 10 years in prison for depriving the inmate's rights, 20 years for the false report and five years for conspiracy.