Credibility, you say? Wall St. Journal is now owned by Rupert Murdoch.
Other criminal probes of airplane crashes? The FBI made a mess of the TWA800 investigation (or coverup). Only "internet conspiracy theorists" believed a missile could have been involved, yet the FBI remained in control long after they had stated it was not foul play. Those pesky internet weirdos, and many, if not most TWA employees, and many close to the investigation never accepted the evidence and conclusions of the official investigation.
GB