PBS Frontline's 'The Untouchables' Investigates Lack Of Wall Street Prosecutions After Mortgage Crisis (VIDEO)

Martin Smith, producer of the new PBS Frontline episode, "The Untouchables," joined HuffPost Live Tuesday to discuss his investigation into the lack of prosecutions of Wall Street executives in the wake of the mortgage-backed securities fueled financial crisis.

Commenting on clips from the episode showing former home loan underwriters explaining how they would laugh as they pushed through mortgages that were too expensive for the borrowers, Smith said this type of behavior was "very frequent and common."

"There are lawsuits that name 35 -- easily 36, 37 -- of these kind of testimonies," Smith told HuffPost Live host Jacob Soboroff. "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."

The episode, which premieres Tuesday night at 10 p.m. on local PBS stations, "investigates why Wall Street’s leaders have escaped prosecution for any fraud related to the sale of bad mortgages," according to the episode description on the Frontline website.