Surrounded by TV cameras outside a federal courthouse, former Massey Energy CEO Don Blankenship stood quietly and let his attorney do the talking after being convicted on a misdemeanor conspiracy charge in connection with the deadliest U.S. mine disaster in four decades. If found guilty of all charges, he could have been imprisoned for up to 30 years. University of Virginia law professor Brandon Garrett said the verdict shows jurors can hold a corporate chief accountable in a complex case.