Say you are a banker who sees a way to make some money for your bank or yourself by cooking the books, or self-dealing, or laundering drug-cartel money, or doing business with known terrorists, or helping Iran escape sanctions. What are your odds of going to prison if caught?

The apparent answer: It depends on the size of your bank.

If you are a small or regional banker and the feds are onto your crime, prison probably awaits. Just one federal agency, the Special Inspector General for the Troubled Asset Relief Program (SIGTARP), from 2009 through the first three months of this year, has indicted 188 bankers, including 123 senior officers, on criminal charges, has obtained 129 convictions, and has banned 94 individuals from banking, finance and related industries. These are bankers who allegedly tried to cheat taxpayers by misusing bailout money.

But if you work for a large multinational banking institution of the sort considered "too big to fail," and you helped sell "troubled assets," launder money or evade sanctions, the odds are you will get off with at most a rap on the knuckles.

Not one senior officer of a major bank has been successfully prosecuted during the Obama Administration.

Considering the enormous pain and suffering that the 2008 financial crisis inflicted on the nation and the strong likelihood that some senior bankers knew or should have known that their banks were trading in what amounted to fraudulent securities, that failure to prosecute is hard to understand.

Even worse, when Britain's largest bank, HSBC, was caught laundering drug-cartel money, evading Iran sanctions and doing business with terrorist-related institutions, the Justice Department simply imposed a large fine. While Justice officials said that HSBC bankers committed criminal acts, the authorities acted as if it the bank itself was at fault but was also "too big to jail."

That's because if found guilty the bank might lose its charter, destabilizing the financial system.

Criticism of the failure to bring criminal charges in the HSBC case must have stung the Obama administration, sensitive to a perception that it is too close to big banks and too reliant on political contributions from the financial sector.

But Attorney General Eric Holder, a former and possibly future corporate lawyer, has chosen an odd way to show that he is tough on banks. Last Monday he posted a video in which he said, "There is no such thing as 'too big to jail' " and "no company ... is above the law." He added that prosecutors are working with regulators to ensure that criminal charges don't lead to "irresponsible" broader consequences for the financial system.

And media reports say the Justice Department and New York banking regulators are considering criminal charges against big Swiss and French banks.

But not against individual bankers.

And that is what makes Mr. Holder's approach so odd. As Federal District Judge Jed Rakoff, a leading authority on financial crimes, wrote earlier this year in an article critical of the Justice Department's failure to prosecute financial crimes, "Companies do not commit crimes; only their agents do."

No, Justice did not show sufficient resolve in prosecuting wrongdoing by big bankers under previous administrations, either.

But to focus criminal investigations on institutions rather than on individual law-breaking bankers is to go after the wrong target. Bank shareholders, the vast majority of whom are wholly innocent, might be forced to pay the only real penalties.

Worse, such a policy sends the wrong signals to bankers, who may see that they can commit crimes with impunity.

As Christy Romero, the special inspector general of TARP, notes in her most recent report to Congress, prosecuting bankers who break the law strengthens the financial system, deters future law breaking and reduces the risks of failure.

Attorney General Holder should be asked to explain his upside-down approach to banking crimes - and urged to hold even the big bankers who break the law accountable for their crimes.