Ferdinand Pecora was little known outside New York until 1933. The former New York prosecutor was called to Washington to become chief counsel of Senate hearings looking into Wall Street's wrongdoings that led to the Crash of 1929. Pecora is a surprising hero of the time -- he was a poor Italian immigrant who earned his legal education at night school. And over a ten-day period, he grilled some of the titans of Wall Street, toppling one of them -- multimillionaire Charles Mitchell, aka Sunshine Charley -- who was chairman of National City Bank, the predecessor of the current-day Citibank. NPR's Robert Siegel talks to Michael Perino, a law professor and former Wall Street litigator, about his new book, The Hellhound of Wall Street: How Ferdinand Pecora's Investigation of the Great Crash Forever Changed American Finance.