In 'The Untouchables,' the PBS series 'Frontline' investigated why Wall Street's leaders have escaped prosecution connected to the 2008 crash, which included massive fraud related to the sale of bad mortgages (video below).

Producer Martin Smith told HuffPo Live on Tuesday (video below) that former home loan underwriters would laugh as they pushed through mortgages that were too expensive for the borrowers.

Smith said: "There are lawsuits that name 35, easily 36, 37, of these kind of testimonies. And these guys are joking about it at this point, but of course it's not really funny in the end because it all resulted in the collapse of 2008, a million people losing their houses, many people out of work and businesses seeing demand sink."

One former loan underwriter told Frontline: "It was like a party. We were getting through these loans as quick as we can. They were not being looked at like they should've been looked at."

As the Obama administration took power, Wall Street leaders lawyered up and expected to be charged with numerous crimes, but the prosecution never happened.