How can I set a trap to prevent workers from stealing from our store safe?

Question

I have a envelope drop safe like this http://www.nationwidesafes.com/sdb104.html

that we use at our business. I do not own the business, however I am the location manager. We have auditors that randomly (2x a week) collect our deposits and an assistant manager to work in the store on my off days. The auditors are supposedly 'tested and polygraphed' randomly so they are trusted by the upper management. Anyhow, I have had 1100 dollars stolen in the past five weeks from the safe. I have accurately made every deposit, however my drops are coming up "short" and they coincidentally find these errors every time I'm off. There are no cameras in our store, and the only ones who have access to the safe are the auditors. I guess I'm trying to figure out a way to trap them so I don't have to keep paying for what someone else is stealing. That's right. The upper management is saying I am responsible for it.

PS We put the checks, cash, credit card receipts, etc into a resealable envelope then deposit it into the safe. Can anyone help me with a trap or some intelligent means of catching these criminals?

Answer 1

If you make all of the drops, then just make sure you are there when the auditors pick up the money, and have them count it in front of you. You could also create a sign off sheet to better help your case, so after the money is counted you both sign the sheet with the date and amount, that way when they leave the store you can no longer be held responsible. As far as employees go you could always set up a system so that you see all deposits before they are deposited. Otherwise cameras would be your best bet.

Answer 2

cameras are the only way  

Answer 3

Set up your own camera since the company won't take an interest in it.