… Very disciplined criminals are few and far between….
Just so! (See below.)
… There was once a man who forged banknotes. …
This strikes a chord. My father's paternal uncles were all crooks (all of them died before I was born in the mid-forties), and several of them were anything but petty. The most gentlemanly and least physically dangerous of them was a man whom his brothers and associates nicknamed Rube—because that's what he was ("Rube" is an old crooks' demimonde slang term; look it up if you're interested).
Uncle Rube was by all accounts a world-class forger. According to both my father and my grandmother (who incidentally liked Uncle Rube the best of all her in-laws: "he was a sweet man"), when he came out of the slammer for the third time, half a dozen New York banks offered him a job that involved nothing more than coming into the office a few hours a week to look at and give his expert opinion on questionable-looking bills that had been deposited. Their true aim, of course, was to buy him off and thus, hopefully, keep him from returning to his old "profession."
As my grandmother put it, Uncle Rube turned the banks down flat for no other reason than that the very idea of working for a living in the straight world was simply too much for him to handle. Within a year of becoming free again, finding himself short of cash, he returned to his backup occupation as a "dip" (a pickpocket). Unfortunately, though he was a great forger, he was a lousy dip. He was caught with his hand in someone else's pocket and arrested almost immediately, and as a three-time loser, he was automatically sentenced to life in prison, where he very soon after died.
Would anyone on this forum tell the authorities if they had reason to suspect that someone was an illegal immigrant working in the United States?
I would. Not that it would do much good, alas.