Rockmond Dunbar is adding another law enforcement gig to his resume.

The actor - who has portrayed the sheriff of Charming on Sons of Anarchy for the past two seasons - has been cast as Dennis Abbott on The Mentalist.

CBS sources describe the FBI agent to Deadline as possessing "a no-nonsense" attitude and as being unimpressed by Patrick Jane’s skills and/or charm.

Dunbar will recur on Season 6 - on episodes 7, 8 an 9, to be exact - but has the potential to end up as one of two new series regulars on the CBS hit.

Much to the surprise/chagrin of fans, Amanda Righetti and Owain Yeoman are both exiting the drama and creator Bruno Heller has said replacement characters are on the way. At least one will be female.

The Mentalist returns with new episodes on Sunday, September 29.

Matt Richenthal is the Editor in Chief of TV Fanatic. Follow him on Twitter and on Google+.