Numb3rs actress Diane Farr will play the owner of a winery, TV Line reports.
Meanwhile, NYPD Blue's Bonnie Somerville will portray Farr's character's business partner, with The West Wing's Kathryn Joosten playing the murder victim's neighbour.
True Blood actor James Frain will also appear in the episode, which is due to air in February.
This season's guest stars have included Craig Bierko, E.T star Henry Thomas and The Shield star Reed Diamond.
Diamond's Shield co-star Catherine Dent has also signed up for a recurring role on the show.
Last week, Morena Baccarin teased her upcoming return to the CBS series, describing her character Erica Flynn's reunion with Patrick Jane (Simon Baker) as "really juicy".
The Mentalist will return with new episodes on January 12, 2012.
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