An audio version of FRONTLINE’s documentary “The Untouchables” airing January 22 2013 on PBS and available for viewing online at pbs.org/frontline. FRONTLINE producer and correspondent Martin Smith investigates why the U.S. Department of Justice (DOJ) has failed to act on credible evidence that Wall Street knowingly packaged and sold toxic mortgage loans to investors, loans that brought the U.S. and world economies to the brink of collapse. Through interviews with prosecutors, government officials and industry whistleblowers, the film raises questions over whether senior bankers either ignored or contributed to fraud while inflating the bubble through the purchase and securitization of loans.