set a thief to catch a thief

set a thief to catch a thief

To employ a criminal or thief in order to understand, anticipate, and ultimately apprehend another criminal or thief. Honestly, who better to lead an investigation into tax fraud than someone who was convicted of just that? Set a thief to catch a thief, I say. We've actually begun employing prominent members of the hacking community to improve our cyber security, setting thieves to catch thieves, as it were.
See also: catch, set, thief
Farlex Dictionary of Idioms.

Set a thief to catch a thief.

Prov. The best person to catch a thief is another thief, because he or she knows how thieves think. The government set a thief to catch a thief, hiring a stockbroker convicted of fraudulent practices to entrap the stockbroker they were investigating for fraud.
See also: catch, set, thief
McGraw-Hill Dictionary of American Idioms and Phrasal Verbs.
See also:
  • stool pigeon
  • stoolie
  • a stool pigeon
  • throw the book at
  • throw the book at (one)
  • throw the book at somebody
  • throw the book at someone
  • eel
  • (as) slippery as an eel
  • make (one's) bones
References in periodicals archive
Set a thief to catch a thief. Scientists trying to combat HIV have taken that message to heart and created novel viruses that infect only cells the AIDS virus has already broken into.