TV Guide reports that the actor will play Agent J.J. Laroche, the head of CBI Internal Affairs, in five or six episodes.
The character is described as "quirky, charmless, professional [and] socially awkward" and will become a rival to Patrick Jane (Simon Baker) when a CBI employee comes under suspicion.
Vince previously starred as Mose Manuel on HBO series Deadwood and recently made a guest appearance on TNT cop drama Memphis Beat.
The Mentalist continues on Thursdays at 10/9c on CBS. Vince will make his first appearance on December 9.