Remember it didn't work for Vincent 'The Chin' Gigante, the boss of the Genovese crime family who wandered around the street in his bathrobe, trying to fake crazy. Pelosi can be shown competent enough to stand trial.
"[Mueller] supervised such high profile cases as the prosecution of Panamanian strongman Manuel Noriega and organised crime boss John Gotti. And he led the investigations of the 1991 collapse of the Bank of Credit and Commerce International banking and the 1988 bombing of Pan Am 103."
http://news.bbc.co.uk/2/hi/americas/1424760.stm