That would appear to be

CAPLIN & DRYSDALE, CHARTERED, Petitioner v. UNITED STATES.

http://bulk.resource.org/courts.gov/c/US/491/491.US.617.87-1...

Thanks, I had a feeling it would be something like this. Looking it over that case clearly doesn't apply to this situation- the defendant there plead guilty, so it was already known that the money was illegitimately earned doing criminal activities.