'CSI': Conor O'Farrell to Return for Season Finale (Exclusive)

Connor O'Farrell Screengrab - H 2012

Connor O'Farrell Screengrab - H 2012

CBS' CSI: Crime Scene Investigation is welcoming back a familiar face.

Conor O'Farrell will reprise his role as Undersheriff Jeffrey McKeen in the May 9 season finale of the long-running procedural, The Hollywood Reporter has learned exclusively.

In the season finale (titled "Homecoming"), O'Farrell will resurface when a friend of the sheriff (Prison Break's Barbara Eve Harris) becomes a prime suspect in his wife's brutal murder and the investigation's political fallout reveals the truth behind Russell's (Ted Danson) troubled history with Finlay (Elisabeth Shue).

O'Farrell first appeared on the CBS staple in the Season 5 finale (directed by Quentin Tarantino) and recurred as the undersheriff. He last appeared in the Season 9 premiere when McKeen shot and killed Warrick Brown (Gary Dourdan) after he was accused and cleared of the slaying of a famous mobster. In the Season 9 opener, the team discovered it was McKeen, and Nick Stokes (George Eads) ended up taking him down.

O'Farrell, whose credits also include Justified, Rizzoli & Isles and Lie to Me, is repped by SDB Partners.

CSI airs Wednesdays at 10 p.m. on CBS.

Email: Lesley.Goldberg@thr.com; Twitter: @Snoodit