The U.S. Supreme Court denied the petition of former Massey Energy CEO Don Blankenship to review his misdemeanor conviction of conspiracy to violate mine safety laws Oct. 10.

Blankenship appealed to the high court to review a 4th Circuit Court of Appeals decision shortly after he concluded a one-year prison sentence. The former coal boss has insisted the charges against him were based on an aggressive prosecution and dishonest investigations that shifted blame from federal officials. The investigation stemmed from the 2010 explosion at the Upper Big Branch mine that killed 29 coal miners in West Virginia.

In mid-September, attorneys of the former coal executive said prosecution of corporate officials could be easier if the U.S. Supreme Court does not reverse their client's misdemeanor conviction.

Blankenship's lawyers have asked the high court to review technical aspects of the case, including whether instructions to the jury regarding "criminal willfulness" were inappropriate. They claimed the court allowed the jury to convict on a determination that Blankenship, the CEO of Massey Energy at the time of the explosion, was negligent or reckless in setting budgets for staffing and production without requiring a finding that he had known his conduct was unlawful or that he intended to violate the law.

"Because the rationale of the court of appeals' published opinion could be applied in future cases — especially in prosecutions of corporate officials — to any criminal statute that criminalizes only willful conduct, the court should summarily reverse," the reply brief states.