Reuters reports the Justice Department is getting ready to file civil fraud charges against Citigroup (C) and Bank of America’s Merrill Lynch (BAC) unit. The charges are related to the banks selling flawed mortgage securities to investors ahead of the financial crisis.

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It’s a continuation of mortgage-related cases stemming from a 2012 government task force the Obama Administration dedicated to investigating these issues.

Probes against Royal Bank of Scotland (RBS) and Credit Suisse (CS) are also reported to be underway.

These developments come after J.P. Morgan Chase (JPM) last month reached a $13 billion settlement with the DOJ to resolve charges stemming from the same issue -- the bank overstating the quality of mortgages it was selling to investors.

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In an interesting plot twist, you might say J.P. Morgan has fired back.

JPM has sued the Federal Deposit Insurance Company for more than $1 billion over the bank’s purchase of Washington Mutual at the height of the financial crisis. JPM alleges in its suit that the FDIC receivership has not honored its obligations to absorb certain legal claims related to WaMu.

To recap briefly: WaMu was the biggest commercial-banking failure in the U.S. history. The FDIC chose JPM’s bid in 2008 to buy WaMu’s banking operations. Part of JPM's $13 billion settlement has to do with charges related to WaMu.

Now to be clear, the settlement with the DOJ stipulated that none of the costs paid by J.P. Morgan as a result of the agreement would be passed to the FDIC. According to Alexis Goldstein, the settlement did not preclude JPM from going after the FDIC receivership – which you might think of as the “zombie company” or the remains of WaMu - -that the FDIC winds down. That's where the money is that JPM is seeking in this lawsuit.

“There’s only so much money in this pot, and if the FDIC pays everybody that’s trying to get money out of that pot they’re going to have to exhaust a separate fund … which all of the banks pay into including small community banks,” says Goldstein, who is also communications director for the economic justice nonprofit other98.com. “So J.P. Morgan is trying to get a bunch of money that hedge funds have already laid a claim on, and if they succeed, in a way this is kind of going to be like small community banks bailing out JPM.”

So does J.P. Morgan have a case, or does it just have gumption? Check out the video to see Goldstein’s answer to that question.