Five years after the collapse of Enron, Ken Lay and Jeff Skilling are headed for jail. A federal jury in Houston convicted the former Enron chiefs Thursday. Jurors found the men guilty of fraud and conspiracy in the energy trader's 2001 collapse. A Sept. 11 sentencing will decide whether they spend the rest of their lives in prison. Despicable as Lay and Skilling are -- what with the lying, the pumping-and-dumping, the outrageous pay -- perhaps the most galling thing about the scandal was their defense at the trial. "This is not a case of hear no evil, see no evil," Skilling lawyer Daniel Petrocelli insisted in February, The Wall Street Journal reports. "This is a case of there was no evil." Somehow, though, jurors seem to have noticed the guilty pleas entered by more than a dozen other Enron defendants -- many of whom ended up testifying against Lay and Skilling. So come Thursday, Petrocelli was promising a vigorous appeal and rationalizing the jury's decision. "They saw it their way," he said. For his part, Skilling said it's time to "go back and think this thing through." He'll have plenty of time for that where he's going. Dumb-o-Meter score: 95. "This closes the door on the poor-monkey defense," former Securities and Exchange Commission chief Harvey Pitt told CNBC. To view Colin Barr's video take on Enron's entry in Five Dumbest this week, click here .