The New York Times takes a look at Mark Walsh's real estate empire at Lehman Brothers, where he built a reputation as "the most brilliant real estate financier on Wall Street." In the '90s, he pioneered "the art of lending to office building developers and then slicing up and repackaging the debt for investors. Less risky pieces went to institutional investors; the lower-rated chunks to hedge funds and others hungry for juicier returns. Lehman pocketed a fee every step of the way, and it often retained a risky piece or two to give its own earnings a kick."

His unit was said to have created more than 20 percent of Lehman's $4 billion in profits in 2006. But at what cost? Investigators are looking into how Lehman valued its real estate exposure, and some think there were some iffy practices at work. New Jersey has already accused the firm of defrauding its pensions by misrepresenting its real estate exposure. 

For more:
- here's a look at the Walsh empire from the Times