Marg Helgenberger and William Petersen from the cast of CSI sit together at the 14th annual Screen Actors Guild Awards in Los Angeles
Marg Helgenberger (L) and William Petersen from the cast of CSI sit together at the 14th annual Screen Actors Guild Awards in Los Angeles January 27, 2008. REUTERS/Danny Moloshok

Update: Marg Helgenberger: A Look at Catherine Willows' Last 'CSI' Episode [VIDEO]

Fans of the hit TV crime show CSI will be sad to see Marg Helgenberger's character, Catherine Willows, leave. Helgenberger announced last year that she is leaving CSI and is the latest original cast member to do so.

Her last episode will air on Jan. 25, according to reports.

In December, Entertainment Weekly reported that CSI team said their final goodbye to Helgenberger. She has been on the show since 2000 and wrapped her 263rd episode before making her departure.

I've been thinking a lot about this moment for a very long time, Helgenberger reportedly told the cast who gathered for her send off. From the bottom of my heart, thank you for the time of my life.

Helgenberger reportedly kept the vest and badge Willows wore as memorabilia, EW reported.

Oscar nominee Elisabeth Shue will join the cast of CSI to replace Helgenberger.

Shue will appear in her first episode on Feb. 15, according to AolTV. She will be a new investigator joining the team. Rumors are that D.B. Russell, played by Ted Danson, fired her when she worked for him in Seattle.

About Catherine Willows

Willows was level-3 CSI and forensic scientist in Las Vegas. She had a rough upbringing, raised by a single mother who was a waitress and a showgirl. Though very intelligent and witty, Willows never really got the chance to show just how smart she was until years later because her mother's job didn't allow for her to be settled in school.

Willows fell into the nightlife by becoming an exotic dancer. She also had to become the breadwinner for her and her boyfriend, who had nothing but dreams. She also became a single mother and struggled to raise her daughter.

Finally, Willows developed a love for crime scene investigation and returned to school to get a medical science degree from West Las Vegas University.

After graduating university she joined the CSI team at the Las Vegas Police Department, worked her way up from lab technician to a supervisor. Throughout it all, Willows made something of herself under the guidance of her good friend and head of the team, Gil Grissom.

Willows later fell in love with Det. Vartann, played by Alex Carter.

Willows holds the No. 82 position on Bravo's list of 100 Greatest TV Characters and shares the position with Grissom, who was played by William Petersen.