It turns out that Wall St. knew almost one-third of the mortgages they bundled and sold to investors were bad. You're shocked, right? I know I find it hard to believe that this bunch of high-priced suit-wearing cokeheads, these Masters of the Universe would gleefully stiff American investors like that:

During a little-noticed hearing this week in Sacramento, Calif., a firm hired by Wall Street to analyze mortgages given to borrowers with poor credit, which were then packaged and sold to investors during the boom years, revealed that as much as 28 percent of those loans failed to meet basic underwriting standards -- and Wall Street knew all along.

Worse, when the firm flagged those loans for potential issues, Wall Street banks ignored its recommendation nearly half the time and likely purchased those loans anyway -- selling them to unwitting investors who were never told that the biggest home loan due diligence firm in the country had found potential defects in these mortgages.

The revelations give a better picture of what many have likely known for years: Wall Street firms knew they were buying lead yet passed it off as gold to investors who had no knowledge of the alchemy behind the scenes. But it also has real-world implications: the data released Thursday could bolster pension funds and other investors in their pursuit to force Wall Street banks to take back the bogus mortgages they peddled. An untold number of lawsuits have been filed in the wake of the subprime mortgage crisis and subsequent housing market collapse. Thus far, Wall Street has been winning that battle.

Clayton Holdings, a Connecticut-based firm that analyzes home mortgages for banks, hedge funds, insurance companies and government agencies, provided its data Thursday to the Financial Crisis Inquiry Commission, a bipartisan panel created by Congress to investigate the roots of the worst financial crisis since the Great Depression. The FCIC held its last public hearing in Sacramento, the home of the panel's chairman, where two current and former top Clayton executives testified under oath about the firm's role in the mortgage securitization chain.

During the height of the boom in 2006 and the period prior to its immediate end during the first six months of 2007, Clayton inspected home loans for Wall Street firms and government-backed mortgage giant Freddie Mac. Clayton looked at loans that the companies wanted to purchase from mortgage originators like New Century Financial, Countrywide Financial, and Fremont Investment & Loan. The company examined 911,039 mortgages, documents show.

Clients included Bank of America and JPMorgan Chase, the nation's two biggest banks by assets which together have about $4.4 trillion; Citigroup, Deutsche Bank, Goldman Sachs, Morgan Stanley, Bear Stearns and Lehman Brothers. Clayton controlled about 50 to 70 percent of the market, Keith Johnson, the firm's former president, told the crisis panel.

Clayton, though, typically looked at roughly 10 percent of the pool of mortgages available for purchase, Vicki Beal, a senior vice president at the firm, said in response to a question by panel chairman Phil Angelides. But during the frenzied last months of the boom, when lenders and securitizers were trying to sell off as much as they could before the market collapsed, that figure reached as low as 5 percent.

Of the 911,000 loans that Clayton scrutinized, 72 percent either met the mortgage seller's standards and other guidelines set by the buyer of the mortgages, typically Wall Street firms, or they had off-setting factors that allowed Clayton to give them a passing grade, like if the borrower who took out the mortgage put a lot of money down or had a very high income.

But 28 percent failed to meet those standards. Of those 255,802 mortgages that Clayton flagged for what were a variety of reasons, Wall Street ended up waiving 100,653 of them, or 39 percent of those loans that did not meet basic standards. And Wall Street firms didn't share this with investors.

"This should have raised red flags," said Guy Cecala, publisher of Inside Mortgage Finance, a leading trade publication and data provider.