The rule that all business failures become criminal matters is bearing out in the subprime mess. Yesterday we learned of an FBI probe. (Gary Weiss expertly dissects it over on Portfolio.) This morning we learned that New York Attorney General Andrew Cuomo’s office is considering employing the ancient and dreaded Martin Act against Wall Street.

What makes the state law so powerful is that its broad definition of securities fraud doesn’t require a prosecutors to prove intent. It was a favorite weapon of Loathsome Eliot Spitzer when he held the AG’s office. Now Cuomo is looking to use it to show fraud in the packaging of mortgage bonds and derivatives, according to the Wall Street Journal.

“The attorney general's office has issued Martin Act subpoenas, which don't spell out whether matters are civil or criminal in nature, according to people familiar with the matter. So far, the recipients include financial firms Bear Stearns Cos., Deutsche Bank AG, Morgan Stanley, Merrill Lynch & Co., and Lehman Brothers Holdings Inc., possibly among others,” the Journal said.

“When they start using the Martin Act, you don’t run, you don’t hide, you don’t fight. You settle early, and often,” a veteran of an earlier round of Martin Act subpoenas told us.

These investigations can have serious costs for the target banks. Management gets distracted, legal costs skyrocket and settlements usually involve heavy fines. What’s more, the AG office can be much more difficult to deal with than the SEC, and it is much less predictable. Perhaps even more than the SEC, federal prosecutor and FBI investigations, this could spell serious trouble for Wall Street.

State Subprime Probe Takes a New Tack [Wall Street Journal]