I had to rat on someone for the first time ever

I agree with SCredneck,
Since he is a federal employee, that constitutes falsifying a federal document which is a felony.
I quite frankly, would take him aside, place a copy of the evidence in his hands, explain to him how serious his crime is and tell him he has 24 hours to resign, OR the package gets delivered to the nearest Federal prosecutor.
Thats just me
Andrew