We think a solution here could be a Dram Shop Act-style law holding bankers responsible for the crimes committed by those who become “intoxicated” with its products.

As Deutsche Bank officials this year scrambled to extricate themselves from a years-long relationship with Jeffrey Epstein, the wealthy financier charged this month with sex trafficking, they uncovered suspicious transactions in which Mr. Epstein had moved money out of the United States.

Deutsche Bank reported the transactions to a federal agency in charge of policing financial crimes, according to three people familiar with the bank’s internal processes. The report came as the bank started looking for signs that Mr. Epstein was using his financial resources for the purposes of sex trafficking.