How about the fact you are stealing or frauding your customers. You have reduced their bill and they don't know about it. If you reduced my bill, I'd want that money in my pocket, not in yours.
As far as gratiuities issued to LEO's some places have FORMAL agreements or instruction to staff. Here there are places like McDonalds, local coffee shops etc that will look after a wide range of uniform personnel. Some do it for their own reasons, some do it as a result of you working with your local community and they view you as part of that. THere is no deceipt or dishonesty there, unlike your situation.
You have committed systematic and calculated fraud & Theft.
DQ for me.
There are three kinds of lies: lies, damned lies, and statistics.