Most of the laws require a higher standard than I think you can assert simply by absence of the money in the till (1), and require that provisions for deduction not be bundled into any other workplace contract or document (2) -- they cannot, in the states I have been examining, be bundled into the employment contract.
Again, in most states, your remedies as employer are to ( a ) get the employee to sign away their rights without duress and in a document unbundled from any other workplace document (i.e. signing the back of the check does not indicate consent; signing the paperwork to accept the job does not indicate consent). Or ( b ) fire them. Or ( c ) sue them. In most states that I can find, if you can't build a case enough to fire them or sue them, then you eat the loss.
I am not knowledgeable about your practice or your state. This is not about you, per se. (I cannot speak to whether an intent to be a lawyer gives you any special knowledge on these affairs.)
It is about others whose employers may be using such tactics, who may read his and not know that they may have rights. This may not apply to the Amtrak discussion at hand.
David
My intention to become a lawyer was enough played out in coursework that not only did I minor in it, but 3 more credits would have let me double major. I also studied it extensively- while I don't have the ethics (or lack thereof) to be a lawyer, law still fascinates me and like a lot of other things, I study it extensively.
I used extensive cash control aspects in my business. Each cashier was required to use only their assigned register, and each cashier had their own private cash draw that only they could use. It was explained in the hiring process, written into the contract, and yes, even located in a second document entitled "Fiduciary Responsibilities to the Company". All of which were signed and witnessed.
No, I didn't make people pay for bounced checks. That would a be a responsibility of my company, not my agents. Nor do I charge them for other things that they are not responsible for. I was responsible for counting the contents in the drawer at the beginning of each day. They were responsible for double checking the count, and calling me if it was off. They were responsible for taking money in. I would count the drawer again in the evening and check it against the receipt tape. If it was off, that was their responsibility.
I am pro labor myself. I am not a draconian employer. But I do ask that people working for me take responsibilities for their avoidable mistakes. It's nothing less than I ask from myself.
As for the legality of it, I determined it to be legal. I read the laws of which you speak, and based on my interpretation, my practice was in step with them. As you should full well know, no law is written explicitly. They are written to allow for interpretation depending on circumstances. I'm, oh, 85-90% sure it would stand up in court.
I also know I am not the only business to operate this way!