Best known for her television work, Marg Helgenberger started acting in college theatrical productions while studying speech at Northwestern University. A native of Omaha, NE, where she was born on November 16, 1958, Helgenberger moved to New York after graduating from college and landed a role as a tough young policewoman on the soap opera Ryan's Hope. During her four-year tenure on the show, she also maintained her ties with the theater through her involvement with TADA, the Children's Theater Company.
Following a move to Southern California, Helgenberger began guest starring on such television series as Matlock, thirtysomething, and HBO's Tales From the Crypt. She co-starred on the short-lived series Shell Game (1987) before getting her big break with the role of K.C., a tough prostitute, on the distinguished drama China Beach in 1988. Helgenberger's role won her two Emmy nominations and one win in 1990. Following the series' demise in 1991, Helgenberger returned to television guest-star status on ER, where she had a four-episode-long recurring role, and in the miniseries The Tommyknockers.
A presence on the big screen since 1989, when she made her feature-film debut in Steven Spielberg's romantic fantasy Always, Helgenberger has played a wide variety of roles in films ranging from Species (1995) to the moody The Last Time I Committed Suicide (1997) to Steven Soderbergh's widely acclaimed Erin Brockovich (2000). Helgenberger would continue to appear in films like In Good Company and Mr. Brooks, and found particular success with the starring role of Catherine Willows on the long running proceedural CSI: Crime Scene Investigation.