In a two-part episode, Marg Helgenberger will be leaving the cast of "CSI: Las Vegas". Marg joined the cast as Catherine Willows when the show first began in 2000. The pilot episode aired on October 6, 2000. The show is now in its 12 th season.
The character of Catherine Willows began her career with the crime lab as a technician and single parent. Over the years, she worked her way into investigation and finally became the shift supervisor when Gil Grissom, played by William Peterson, left the cast. At the beginning of Season 12, Catherine was demoted from her supervisor position and Ted Danson was introduced as the new supervisor, D.B. Russell. Catherine was welcoming to D.B. and even assisted him as he adapted to his new position.
Catherine's daughter on the series is Lindsey Willows. Lindsey was first played by Madison McReynolds and later by Kay Panabaker. In the third season, Catherine rescues her daughter from drowning when Lindsey and her father, Eddie, were involved in a car accident. Her ex-husband's murder leaves her facing one of the few crimes she is unable to solve. There was not enough evidence left after the car accident. Later in the series, Lindsey's character becomes involved in an investigation of a student that was murdered at her school.
Catherine's mother, Lily Flynn, was a showgirl and over the course of series, it was revealed that Sam Braun was Catherine's father. Sam is the wealthy owner of the Eclipse Casino and connected to much of Las Vegas' rich, famous and infamous. The relationship plays out over time with Catherine first being distrustful of her father and then finally coming to accept him. In Season 7, Sam was shot and died in his daughter's arms.
As a single parent, Catherine has several romantic encounters over the seasons. During the fourth and fifth season, she dated a nightclub owner until she found out he was unfaithful. A hint of romance with CSI Warrick Brown, played by Gary Dourdan, added interest through many episodes. The romance ends when Warrick marries a woman he had just began dating. In Season 9, Warrick told Catherine he was getting a divorce, leaving a potential opening for new romance. Unfortunately, he was then murdered by the Under Sheriff and Catherine was very shaken by his death.
Her last episode on "CSI: Las Vegas" will air on Wednesday, January 25, 2012 at 10 pm ET on CBS. The episode, "Ms. Willows Regrets" on Wednesday, January 18, is designed to lead up to her final appearance. Both Marg Helgenberger and Catherine Willows will be greatly missed by many long-term fans of the show.

