Before leaving for private practice last year, Prosecutor John Hemann e-mailed his colleagues a copy of an open letter addressed to Ryan. He described a staff beset by low spirits and high attrition, and a U.S. Attorney inclined to ignore their concerns.

"There are problems in the office now that have not existed in kind or magnitude since I got here in 1995 ... ," wrote Hemann, who served on the federal Enron task force that prosecuted the company's executives. "It is no solution to deny these problems exist. ...