California Attorney General Jerry Brown has declined to investigate U.S. Senator Charles Schumer’s criticism of IndyMac Bancorp Inc., which some have said caused a run on the Pasadena thrift and its subsequent collapse.

In a letter, Brown told former thrift employees who have called on him to investigate the New York Democrat that he does not believe Schumer’s comments were the cause of the thrift’s failure.

“While we deeply regret the circumstances surrounding IndyMac’s failure, we believe that there is insufficient evidence for us to investigate Senator Schumer at this time,” Brown said in a letter to a former IndyMac employee that was obtained by Bloomberg News.

IndyMac, which federal regulators took over last month, was criticized by Schumer in a June 26 letter to regulators. He said the thrift’s lax lending standards left it on the brink of collapse. Within days of his public release of the letter, depositors withdrew more than $1.3 billion. The run led federal regulators to take control of the bank in July.

Jen Seely, a former IndyMac employee in Northern California, and 50 other former employees sent the letter to Brown requesting an investigation.

Seely’s letter, later distributed by a public relations firm that represents Republican political groups, claimed Schumer’s statements violated a California law prohibiting rumors about the financial health of banks that may jeopardize their solvency. Schumer’s supporters called the charges politically motivated.