thimble rigger
thimble rigger: One who cheats by thimblerigging, or tricks of legerdemain. 1. Also known as a shell game: A game, usually involving gambling, in which a person hides a small object underneath one of three nutshells, thimbles, or cups, then shuffles them about on a flat surface while spectators try to guess the final location of the object. Also called thimblerig. 2. A fraud or deception perpetrated by shifting conspicuous things to hide something else.
"Their notions of justice more closely resemble that of the sidewalk thimble rigger."