BOISE, Idaho (AP) — A federal judge says private prison company Corrections Corporation of America is in contempt of court for persistently understaffing an Idaho prison in direct violation of a legal settlement.

U.S. District Judge David Carter made the ruling Monday in a lawsuit between inmates at the CCA-run Idaho Correctional Center and the Nashville-based company.

Carter wrote that CCA had ample reason to make sure it was meeting the staffing requirements at the prison, yet the level of understaffing was apparently far worse than the company originally acknowledged. He is appointing an independent monitor to oversee operations at the prison, and says steep fines will follow if the company violates the agreement again.

The fines will start at $100 an hour if more than 12 hours are understaffed in a single month.