Marg Helgenberger says goodbye to "CSI" Marg Helgenberger has been a star on "CSI" from the very beginning, and why she would decide to leave a show that's still going strong is a bit of a mystery . . . one of the things John Blackstone will attempt to clear up in a Sunday Profile: Blood spatter, fingerprints and exit wounds have been very good to Marg Helgenberger. She has become one of the highest-paid actresses on television for her portrayal on "CSI" of Catherine Willows, a Las Vegas crime scene investigator with a Las Vegas past. "In the pilot script, in fact, she's described as 'Catherine Willows, CSI 3, single mother, ex-stripper,'" said Helgenberger. Helgenberger is now leaving "CSI." She has been in the series since its first broadcast 12 years ago, when it became a sudden and unexpected hit. "It was put on a Friday night, kind of without a whole lot of fanfare," she recalled. And it just got these incredible numbers. From what I was told, CBS actually kind of had them do the numbers again. They thought there was something faulty about their machinery! There was nothing faulty - and ever since "CSI" has been among the highest-rated shows on TV. It launched two spinoffs and a whole genre of procedural crime shows. Ted Danson and Marg Helgenberger in a scene from the crime drama series "CSI." And it created what came to be called the "CSI" effect: Real juries deciding real cases wondered why criminal investigators couldn't bring more decisive evidence into court. Or as Helgenberger described it, "Why can't you do it like on 'CSI,' you know?" Walking away from a show that is said to have paid her up to $375,000 an episode seems a pretty rash decision. But somehow things always seem to work out for her. Even with a name that just doesn't sound like it belongs in Hollywood. I don't know why I didn't do anything about that way back then!" she laughed. In fact she DID change her name briefly for her first TV job. as the weekend weather girl at a small station in Nebraska. The anchor team consisted of a guy by the name of Harvie Nachlinger. The newscaster was Joyce Eisenminger. So, they didn't want it to be the Eisenminger-Nachlinger-Helgenberger report," she laughed. For that summer she became Margie McClarty, borrowing her grandmother's name. Helgenberger grew up in North Bend, Neb., a little town where she was expected to become a nurse, like her mother. Her first exposure to the stage in school plays was not promising. I didn't really enjoy it at the time. She told Blackstone about her role in a play called "Danny, the Dark Green Dinosaur," in which she portrayed a swan. And I just remember just being terrified. The plays got better, and so did she. In a performance of "The Taming of the Shrew" in college, she was spotted by the casting director for an ABC soap opera, "Ryan's Hope." She was soon on network television. Yeah, it happened pretty quickly before I had a chance to even give it a whole lot of thought. Other roles seemed to come just as easily. She was in the Vietnam-era drama "China Beach," playing K.C. Kolowski, a business woman and prostitute - a role for which she won an Emmy. "Another smart, sexy character," said Blackstone. Is that what you demanded to play? Is that what you've always demanded to play? 'I'm gonna play a smart sexy character'?