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.