Presumably suspend your partner in crimes transaction receipt is printed walk away. Partner slips you some money later. Solution: don't hire scummy people, pay

Presumably suspend your partner in crimes transaction receipt is printed walk away. Partner slips you some money later. Solution: don't hire scummy people, pay enough that you can afford decent folks, watch for a friend that always comes to a certain cashier especially while alone, watch for cashier being nervous when observed, watch for partner to break off transaction if observed, "forget card", or return goods shortly. It's also obviously trivial to catch with the receipt but they will probably refuse to show it. A transaction log will also trivially show it if matched with register and time. Anyone could potentially get away with this once but any dishonest person is going to want to do this repeatedly. There is basically no excuse for not catching this as a manager and I see no reason to deny associates this useful feature.