By VICKI SMITHMORGANTOWN, W.Va. (AP) â¿¿ A federal appeals court on Friday upheld the conviction of an ex-security chief who lied to investigators and ordered a subordinate to destroy documents after the 2010 explosion that killed 29 coal miners at West Virginia's Upper Big Branch mine. Hughie Elbert Stover claimed there was no evidence he knowingly lied when he told investigators that miners were not alerted whenever inspectors arrived, but a panel of the 4th U.S. Circuit Court of Appeals in Richmond, Va., disagreed. The panel hinted at their ruling during a 20-minute oral argument in September, when they challenged Stover's attorney, William Wilmoth. The judges pointed to witnesses at trial and suggested there was an abundance of circumstantial evidence. Stover also argued that the U.S. District Court in Beckley erred in denying his motion for acquittal or a new trial when there was a lack of evidence, and that the government failed to prove he had any criminal intent when he ordered the records destruction. "Substantial evidence supports the jury's conclusion that Stover acted with the required criminal intent when he ordered a subordinate to destroy records in January 2011," the appellate panel wrote. Wilmoth didn't immediately comment on his client's behalf. U.S. Attorney Booth Goodwin, however, said he was not surprised by the outcome, which he called an important victory for miners' safety. "Investigations of mine disasters serve a critical role in making mines safer. To obstruct one of those investigations, especially one involving a tragedy like that at Upper Big Branch, is reprehensible," Goodwin said. "This case," he added, "should be a powerful warning to anyone tempted to interfere with a mine safety inquiry." The explosion at Montcoal was the worst U.S. coal mining disaster in four decades and remains the subject of a continuing criminal investigation. The mine was owned at the time by Massey Energy, which has since been bought by Virginia-based Alpha Natural Resources.