Had 40 checks stolen

[Mr645]

I had 40 outgoing checks stolen from outgoing mail on May 6th. The mailman physically comes into my office and picks up the outgoing mail from a holder on the desk. So somewhere between his hands and being delivered, 40 outgoing checks went missing.
I found out when they started showing up at ATM machines from Vegas to Maryland, with modified names and amounts on them. 5 were deposited, 1 I caught as it was being processed by a Navy credit union and I stopped payment on the rest.