Houston ? After 21 days of testimony and thousands of pages of evidence not to mention two tons of shredded documents it came down to one piece of paper: a memo by Arthur Andersen lawyer Nancy Temple suggesting changes to a press release announcing a revised Enron earnings statement. Temple’s editing, the jury decided, amounted to impeding a government investigation and made Andersen guilty of obstructing justice.

Defense lawyers and prosecutors were stunned by the revelation that a stray memo had become the “smoking gun” that broke the panel’s deadlock and that the testimony of a high-profile prosecution witness had no impact. But jurors were sanguine, sure of the reasoning that led to their unanimous decision to convict the accounting firm.

The offices of the Arthur Andersen accounting firm are shown in Chicago. Arthur Andersen was convicted Saturday of obstructing justice by shredding Enron-related documents.

“Arthur Andersen set about to change things, to alter documents,” said jury foreman Oscar Criner, a computer science professor at Texas Southern University in Houston. “It’s against the law to alter the document with the intent to impair the fact-finding ability of an official proceeding.”

Ten days ago, it was a subdued group that filed into the jury room on the first day of deliberations. There were nine men and three women from all walks of life: A gray-haired airline executive. A maker of floor tiles. A pastry chef who during jury selection admitted he didn’t know what the Securities and Exchange Commission did.

Eventually the jury sent a note to Judge Melinda Harmon. Must we agree on just one corrupt persuader?

Late Friday afternoon, Harmon told the jury that they need not unanimously agree on one corrupt persuader. By that time, their question was moot. “We had agreed on one,” said juror David Schwab.

It was Nancy Temple, because she was “the author of that particular memo that was altered,” Gallo said.