Before joining the FBI, Weissmann oversaw the Enron Task Force from 2002 to 2005, including the prosecution of Jeffrey Skilling, Kenneth Lay and Andrew Fastow. Before that, Weissmann served in the Eastern District of New York's U.S. Attorney's Office, where, according to the Justice Department, he was "instrumental in bringing to justice high-ranking members" of New York's toughest crime families. While a partner at the law firm Jenner & Block in 2008, Weissmann donated a total of $4,700 to the Obama campaign and Victory Fund. Meanwhile, a donor listed as "Andrew Weissman," from the same law firm donated $4600 to Clinton in 2007 and $2,000 to the DNC in 2006.