Elisabeth Rohm

LOS ANGELES (Zap2it.com) Like the swallows returning to Capistrano or Brigadoon awakening from the mist, few things in the world are as regular as the rotation of assistant district attorneys on NBC’s venerable "Law & Order." Elisabeth Rohm’s lengthy run as ADA is set to end during the show’s 15th season.

Rohm, who joined the show in 2001, is contracted for the first 13 episodes of the upcoming season, but her departure may come soon after that point. The actress will be around to help ease newcomer Dennis Farina into the cast, but will then look to other acting opportunities.

Rohm’s tenure as Assistant District Attorney Serena Southerlyn is longer than any of her predecessors. Recent ADAs have included characters played by Angie Harmon, Carey Lowell and Jill Hennessy.

"With a cast and production team that is unrivaled in television, it has been difficult to even consider the idea of leaving ’Law & Order,’" Rohm says. "Sam Waterston has been a great teacher and friend who has taught me about taking risks, and it is time to put that knowledge into action. It is because of ’Law & Order’ that I have so many opportunities come my way." Before coming to "Law & Order," Rohm’s highest profile credits were stints on "Angel" and "Bull." She’s currently shooting the feature "Miss Congeniality II."

Rohm’s decision is just the latest move in a typically tempestuous "Law & Order" off-season. If you’re keeping score at home, Dennis Farina is in, Jerry Orbach is out and Jesse L. Martin is looking to sign a multiyear deal to stick around.