David 01 Jun 2007 from the hollywood reporter By Nellie Andreeva Jeremy Sisto is returning to NBC next season with a starring role on "Law & Order." Sisto, who played the lead on NBC's "Kidnapped" last season, will play a detective on "L&O," which is returning in the fall for its 18th season. "I've watched Jeremy's career evolve and grow, and I am absolutely thrilled that he has decided to join 'Law & Order,' " "L&O" creator/executive producer Dick Wolf said. Sisto is not a stranger to the veteran crime drama. He guest-starred on the show's 17th-season finale last month, playing a defense attorney. He now will play a brand-new character, which is expected to replace Detective Nina Cassady (Milena Govich). Sisto's deal to join "L&O" comes on the heels of Fred Thompson's announcement Wednesday that he is leaving the series, on which he played District Attorney Arthur Branch for the past five seasons (HR 5/31). Sisto, probably best known for his role on Alan Ball's critically acclaimed HBO drama "Six Feet Under," co-stars in Adrienne Shelly's indie romantic comedy "Waitress." He is repped by ICM and manager Robert Stein.