Imagine joining the Secret Service thinking you're going to be a "hero" protecting the president and then you get some desk job following the paper trail of some common thief (exceptional thief). I'm sure it's happened more than once or twice.

I bet they all know that it is part of the treasury department. They only actually do counterfeiting of currency there are other agencies for financial crimes. Tax evasion would be the IRS and money laundering would likely end up with the FBI.