In places where gambling is legal, there are usually policies by the government to guide the casinos in that regards but the challenge has always been with some casinos trying to be smart about it because at some point they do benefit from the money launders and that has been why the casinos sometimes takes the blame when such happens because they may be aware but literally did almost not or tried to cover it up without handling it accordingly as prescribed by the government policies which was supposed to guide them in that regards.
If regulators are effective at doing their job, issues like this wouldn’t happen. Casinos would be required to register the addresses they’re using, and regulators could verify transactions to ensure none are coming from suspected money launderers without being reported by the casino.
That kind of offense is extremely serious, and no casino would risk it. Regulators have the power to shut down a casino with a single command, so operators wouldn’t dare mess up or ignore compliance requirements.