Richard Causey, the last of the top Enron Corporation executives to learn his punishment, has been jailed for five-and-a-half years for his role in one of the biggest corporate scandals in US history.

Jurors who will decide whether former Enron Corp. chiefs Kenneth Lay and Jeffrey Skilling are criminals face a months-long journey into the heart of the scandal-ridden company. They’ll also face questions about just how illusory the “new-economy” powerhouse was in its glory days.