Is there such a thing as a “professional money launderer,” and do criminals hire specialists to launder money for them?

Yes. There are many such players in the banking and payments world that do this for a living. Needless to say, they don’t openly advertise themselves.

A lot of them are masked behind foreign off-shore shell companies where finding the identity of the true people behind them is almost impossible.

Professional money launderers take a hefty fee (depending on the market) for whitening their money.

One such example of such a professional launderer is Altaf Khanani. You can briefly see this story (a little over exaggerated and dramatized, but the gist of it remains the same).

https://www.youtube.com/watch?v=...

There is also the FATF report on the same.

You can read this report here: http://www.fatf-gafi.org/media/f...