Some lawmakers have accused the Justice Department of avoiding harsh punishments for major Wall Street institutions out of concern over what that turmoil could do the broader financial market. In a letter sent to Holder in January, Sens. Sherrod Brown (D-Ohio) and Charles Grassley (R-Iowa) wondered if such a policy is effectively making some banks "too big to jail."
Waters said she too would want to see some criminal prosecutions brought down on Wall Street misbehavior, but said Justice officials have told her that there is sometimes a lack of evidence to prove that traders acted with criminal intent.
Federal regulators have brought forward a number of cases and achieved numerous settlements from Wall Street institutions for actions leading up to the financial crisis. On Wednesday, the Justice Department and Commodity Futures Trading Commission (CFTC) struck a settlement with the Royal Bank of Scotland over its long-running efforts to manipulate a key interest rate. Between British and U.S. regulators, the bank agreed to pay $612 million in penalties.
The Justice Department also recently brought a civil suit against the credit rater Standard & Poor's, accusing it of fraudulent behavior in assigning top-shelf credit ratings to a range of mortgage-backed financial products that ultimately proved worthless. The credit rater has vowed to fight those charges.