Hughart and May are both cooperating with prosecutors and Assistant U.S. Attorney Steve Ruby has said in court filings that "notable progress has been made in the investigation" that focuses on the Upper Big Branch explosion, but has expanded to include Massey-wide safety practices.

Investigators blamed the Upper Big Branch deaths on a Massey pattern of violating federal standards concerning mine ventilation and the control of highly explosive coal dust, setting the stage there for a small methane ignition to turn into a huge, coal dust-fueled explosion.

In its report on the disaster, MSHA said that advance notice of agency inspections allowed Massey "to conceal violations from enforcement personnel" and permit hazards to go uncorrected.

During trial, four of Stover's security guards testified that they were trained to announce inspectors' arrival over a radio channel audible in the Upper Big Branch Mine office. Two dispatchers testified that they were routinely instructed to relay those announcements to workers underground.

But when Stover was interviewed by investigators -- who had already talked to several of his guards -- he said that Massey's policy and practice was never to announce inspections.

"One thing that is hammered into our head: You do not ask inspectors where they're going, and you do not call the mines," Stover told investigators in a Nov. 30, 2010, interview. "You do not notify anyone when inspectors come on the property."

Stover's lawyer, William Wilmoth, did not immediately respond to a request for comment.

U.S. Attorney Booth Goodwin said in a statement, "This case is an important victory for the safety of miners, so today's decision is a welcome one.

"Investigations of mine disasters serve as a critical role in making mines safer," Goodwin said. "To obstruct one of those investigations, especially one involving a tragedy like that at Upper Big Branch, is reprehensible.

"The evidence against Mr. Stover was overwhelming," Goodwin continued, "so I am not surprised that his conviction was upheld in all respects. This case should be a powerful warning to anyone tempted to interfere with a mine safety inquiry."

Reach Ken Ward Jr. at kw...@wvgazette.com or 304-348-1702.

CHARLESTON, W.Va. -- A federal appeals court on Friday upheld the conviction of a former Massey Energy security director who was found guilty of lying to investigators and trying to destroy evidence following the deaths of 29 miners at Massey's Upper Big Branch Mine in April 2010.

Hughie Elbert Stover had appealed to the 4th U.S. Circuit Court of Appeals after he was sentenced to three years in prison for his conviction during a jury trial in October 2011.

A three-judge panel of the Richmond, Va.-based court unanimously rejected Stover's appeal, which had argued the security director's own statements to UBB investigators should not have been allowed to be used at trial because he had not been read his rights.

"The undisputed record indicates that when Stover was deposed in November 2010, he appeared under a state-issued subpoena, he was represented by counsel, no law enforcement officers were present, the deposition was conducted at a mining academy and not a police station, and that nothing prevented him from simply leaving the deposition," wrote U.S. District Judge Max Cogburn of North Carolina, who took part in the case.

Cogburn was appointed by President Obama. Other judges on the panel were J. Harvie Wilkinson, a Reagan appointee, and Andre Davis, who was appointed to district court during the Clinton administration and to the appeals court by Obama.

Last year, U.S. District Judge Irene Berger sentenced Stover to 36 months in jail, two years of probation and a $20,000 fine after he was convicted of two felonies: making a false statement and obstructing a government probe of the Upper Big Branch Mine Disaster.

Stover was found guilty of lying to investigators about Massey's practice of warning underground workers when government safety inspectors arrive at its mines. A federal jury also concluded that Stover later tried to have one of his guards get rid of company documents about security procedures at Upper Big Branch.

Allegations about "advanced warning" by Massey of federal Mine Safety and Health Administration inspections have become central to the ongoing federal criminal investigation of the worst U.S. coal-mining disaster in nearly 40 years.

Former Upper Big Branch superintendent Gary May is awaiting sentencing after he pleaded guilty to plotting "with others known and unknown" to put coal production ahead of worker safety and to conceal the resulting hazards by warning miners underground in advance of government inspections.

And former longtime Massey official David C. Hughart has agreed to plead guilty to two criminal charges, including taking part in a decade-long scheme involving advance notice of MSHA inspections.

Hughart and May are both cooperating with prosecutors and Assistant U.S. Attorney Steve Ruby has said in court filings that "notable progress has been made in the investigation" that focuses on the Upper Big Branch explosion, but has expanded to include Massey-wide safety practices.

Investigators blamed the Upper Big Branch deaths on a Massey pattern of violating federal standards concerning mine ventilation and the control of highly explosive coal dust, setting the stage there for a small methane ignition to turn into a huge, coal dust-fueled explosion.

In its report on the disaster, MSHA said that advance notice of agency inspections allowed Massey "to conceal violations from enforcement personnel" and permit hazards to go uncorrected.

During trial, four of Stover's security guards testified that they were trained to announce inspectors' arrival over a radio channel audible in the Upper Big Branch Mine office. Two dispatchers testified that they were routinely instructed to relay those announcements to workers underground.

But when Stover was interviewed by investigators -- who had already talked to several of his guards -- he said that Massey's policy and practice was never to announce inspections.

"One thing that is hammered into our head: You do not ask inspectors where they're going, and you do not call the mines," Stover told investigators in a Nov. 30, 2010, interview. "You do not notify anyone when inspectors come on the property."

Stover's lawyer, William Wilmoth, did not immediately respond to a request for comment.

U.S. Attorney Booth Goodwin said in a statement, "This case is an important victory for the safety of miners, so today's decision is a welcome one.

"Investigations of mine disasters serve as a critical role in making mines safer," Goodwin said. "To obstruct one of those investigations, especially one involving a tragedy like that at Upper Big Branch, is reprehensible.

"The evidence against Mr. Stover was overwhelming," Goodwin continued, "so I am not surprised that his conviction was upheld in all respects. This case should be a powerful warning to anyone tempted to interfere with a mine safety inquiry."

Reach Ken Ward Jr. at kw...@wvgazette.com or 304-348-1702.