Things are HEATING up for Goldman Sachs.

Federal prosecutors are conducting a criminal investigation into whether Goldman Sachs Group Inc. or its employees committed securities fraud in connection with its mortgage trading, people familiar with the probe say. The investigation from the Manhattan U.S. Attorney's Office, which is at a preliminary stage, stemmed from a referral from the Securities and Exchange Commission, these people say. The SEC recently filed civil securities-fraud charges against the big Wall Street firm and a trader in its mortgage group. Goldman and the trader say they have done nothing wrong and are fighting the civil charges.

UPDATE:

More info from WaPo which says that the SEC has referred the Goldman case to the Justice Department.

The Securities and Exchange Commission has referred its investigation of Goldman Sachs to the Justice Department for possible criminal prosecution, less than two weeks after filing a civil securities fraud case against the firm, according to a source familiar with the matter. Any probe by the Justice Department would be in a preliminary stage. No Goldman Sachs employees involved in the mortgage-related transactions that are the focus of the SEC case have been interviewed by Justice Department prosecutors or the FBI agents who often conduct probes on behalf of prosecutors, according to a source familiar with the matter.

I wonder how Goldman Sachs' stocks will do tomorrow:

It is very rare for the government to indict a firm, and the mere threat of criminal prosecution can destroy a company. A criminal investigation destroyed the infamous Wall Street firm Drexel Burnham Lambert in the 1980s even though the firm settled with authorities.

WaPo article explains how much more difficult the criminal probe will be vs the civil case: