A criminal investigation is being conducted at Patriot Coal’s Federal No 2 Mine in Monongalia County. John Renner, a Federal No 2 mine foreman who pleaded guilty for false methane readings, is now cooperating with investigators. Sentencing for Renner that was originally scheduled for early August, has been postpone until Jan. 4, 2011. He faces up to five years in prison and a $10,000 fine.