US attorney for the Southern District of West Virginia Booth Goodwin told West Virginia news service MetroNews this week that its team of lawyers and agents are making “enormous progress” on the examination of the blast that took 29 miners’ lives in April 2010.

Reports have already been released by an independent panel appointed by former West Virginia governor Joe Machin, the United Mine Workers of America, former mine owner Massey Energy and, most recently, the US Mine Safety and Health Administration.

In MSHA’s probe document, federal officials called the explosion “entirely preventable” and cited several insufficient mining practices as contributory causes of the incident.

However, Booth told MetroNews, those reports alone – despite their findings – is not sufficient enough to log criminal charges against those responsible, as the agency’s prosecutors need solid evidence.

“There seems to be this misconception out there that the various reports already issued provides us with that evidence,” Goodwin told the paper.

“In other words, a ready-made case has been handed to us and we, simply, failed to charge it. That's just not accurate.”

He said that the office’s position is that the allegations contained in the other reports already released need “much more” investigation in order to both bring charges and win convictions. Also, other probes were not criminal investigations.

The US Attorney’s office continued its investigative work and, while Goodwin did not provide a timeline for the release of any report or charges, he told the news service that he realizes the frustration some have as the UBB explosion nears its two-year anniversary.

“We have a very high standard of proof that we have to meet,” he said.

“I'm not saying that we won't get there … I'm not saying when we'll get there, but people have got to understand that it takes some time. We need to move carefully rather than quickly.”