Mary Beth Buchanan, the Bush-appointed federal prosecutor who had a cameo in the U.S. attorney firings scandal and was charged with pursuing politically motivated prosecutions, is stepping down.

Buchanan, a Republican, is said to be mulling a run for Congress against incumbent Democrat Rep. Jason Altmire. In a statement yesterday, she said she was "looking forward to the next chapter of my professional career," without elaborating.

Since being appointed in 2001 as U.S. attorney for western Pennsylvania, Buchanan has earned a reputation as a loyal Bushie. While leading the Executive Office of U.S. Attorneys in 2005, she was one of the officials consulted by Kyle Sampson, top aide to Alberto Gonzales, when Sampson was drawing up a list of U.S. attorneys to fire, according to Sampson's testimony to Congressional investigators.

She has also been accused of pushing politically motivated prosecutions against local Democrats, most notoriously in the case of Cyril Wecht, a former county coroner and Pennsylvania Democratic fundraiser, who Buchanan prosecuted for misusing his office for political gain. The jury foreman in Wecht's trial publicly called the case "politically driven," and the charges were ultimately dropped earlier this year.

Wecht's lawyer yesterday told the Pittsburgh Post-Gazette: "I think her tenure has stripped that office of its reputation."

And Wecht himself said: "What happened cannot be undone. It would be absurd and extremely hypocritical of me to say, 'All's over and forgiven.' I don't wish her well."

Just this month, a federal public defender charged that Buchanan's office failed to notify defense lawyers after inadvertently receiving recordings of privileged communications between defendants and their attorneys.