MORGANTOWN, W.Va. (AP) -- A former president of Massey Energy's White Buck Coal Co. will enter a plea on federal conspiracy charges in January as prosecutors continue to investigate the 2010 explosion at another Massey operation that killed 29 men.
David C. Hughart is set to appear Jan. 16 before U.S. District Judge Irene Berger in Beckley.
Hughart is cooperating in the continuing investigation of the Upper Big Branch mine disaster in Montcoal. The explosion at that Massey mine, now sealed but owned by Virginia-based Alpha Natural Resources, was the worst U.S. coal mine disaster in four decades.
Prosecutors say Hughart worked with unnamed co-conspirators to ensure miners at White Buck and other, unidentified Massey-owned operations, got advance warning about surprise federal inspections many times between 2000 and March 2010.
They say that gave workers time to conceal life-threatening violations that could have led to citations and shutdowns.
Hughart faces two charges: felony conspiracy to defraud the government by impeding the Mine Safety and Health Administration, and misdemeanor conspiracy to violate mandatory health and safety standards. He faces as long as six years behind bars.
Hughart's cooperation is a sign that authorities may be gathering evidence to target officials further up the Massey hierarchy. Some victims' families hold former CEO Don Blankenship personally responsible, though prosecutors have declined to say who else could face charges in the wide-ranging and continuing probe.
Although Upper Big Branch is never directly mentioned in the case against Hughart, U.S. Attorney Booth Goodwin has said the charges stem from that investigation. The nature of the allegations also parallel charges brought against those who were directly involved with UBB.
Hughart is the third person to face serious criminal charges in connection with Upper Big Branch.
Former superintendent Gary May is also cooperating with prosecutors. He was scheduled to be sentenced Jan. 17, but last week, Goodwin filed a motion to delay that.
May continues to provide important cooperation in the criminal probe, Goodwin said, adding that notable progress has already been made. Delaying his sentencing "will allow that progress to be extended and will avoid any risk to the investigation from the sentencing proceeding itself," he said.
Former Massey security chief Hughie Elbert Stover, meanwhile, is appealing his conviction last fall on charges he lied to investigators and ordered a subordinate to destroy documents.
He was sentenced to three years behind bars — one of the stiffest punishments ever handed down in a mine safety case — but has been free pending appeal. Witnesses testified that Stover instructed mine guards to send radio alerts whenever inspectors entered the property.
He's denied any wrongdoing.