Most casinos have a "big deal wheel" under some name that has a highest payout that increases over time (and resets when it is won). If it is your lucky day, then you likely walk into a casino when the payout hasn't been claimed in a few days. That payout can be in the double digit $millions. All it takes is 1 pull and you won. This will raise no suspicion because most people only get 1 pull on it and someone has to win it some time. The loss is already in their balance sheet. So, they won't be coming after you unless you hit more than one casino.
That is, unless they are specifically looking for lucky people for some other purpose. Then the "big deal wheel" might just be a way to give them a list of people for further study.
You might be able to have them deposit that money into a FOREX or day trader account and multiply it some (10% increase per trade isn't that great on $$100\$100.00 but it's pretty nice on $10,000,000). It all depends on how long it takes to get the money into your account. If it comes to it, you can likely find someone to give you cash now (at a lower amount) for the prize you just won. Heck the casino might do it and consider it a profit (the loss of the full amount is already on the books).
As for a noticeable winning streak using other methods, the casinos can kick you out for any or no reason. "We have the right to refuse service" is a fairly ingrained concept in US businesses. They can also ban you and send your name and photo to the other casinos. All of this is legal and common practice.
As far as back room knuckle breakers, that's not legal action so it depends on the story.
[Note: the double dollar signs ($$) is because having two $ characters in a sentence above caused them to be stripped out and trigger bolded italics between them.]
