OED entry for artful saysThis use began in 1659, and is still popular today. Maybe Dickens in 18somethings?2. a. Skilfully adapted for the accomplishment of a purpose; ingenious, clever. Hence: cunning, crafty, deceitful.
b. Of a person: skilful in adapting means to ends, so as to secure the accomplishment of a purpose, adroit. Hence: skilful in taking unfair advantage; using stratagem; wily, cunning, crafty, deceitful. Cf. Artful Dodger n. at Special uses.
Now the most common sense.
I think it's easy to derive fraud-, rip-off-, and short-change-artist from con-artist, so maybe when artful came to describe "skillfully deceitful", "artist" could then naturally describe someone who was so skilled.
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