1) Boss at the jewelry store 2) Cabal boss 3) Chief instigator 4) Chief miscreant 5) Chief plotter 6) Chief troublemaker 7) Crime boss 8) Criminal mastermind 9) Firebrand 10) Gang boss 11) Head of a cabal 12) Head of a gang 13) Inciter 14) Instigant 15) Instigator 16) Mischief-making mastermind 17) Principal troublemaker 1) Instigator 2) Leader 
A ringleader is a leader of a group of people. Ringleader may also refer to: ...
• (n.) The leader of a circle of dancers; hence, the leader of a number of persons acting together; the leader of a herd of animals. • (n.) Opprobriously, a leader of a body of men engaged in the violation of law or in an illegal enterprise, as rioters, mutineers, or the like.
Ring'lead`er noun 1. The leader of a circle of dancers; hence, the leader of a number of persons acting together; the leader of a herd of animals. « A primacy of order, such an one as the ringleader hath in a dance.» Barrow. 2. Opprobriously, a leader of a b...
[n] - a person who leads (especially in illicit activities)
noun a person who leads (especially in illicit activities)