Catherine Willows (previously
Flynn) is a fictional character from the
CBS crime drama , portrayed by
Marg Helgenberger. She made her first screen appearance in the show's
pilot, broadcast on October 6, 2000. Catherine was a crime scene investigator and forensic scientist for
Clark County, Nevada, until she accepted a job with the
FBI. Helgenberger announced her departure in 2011, with Catherine making her last appearance in the episode "", which aired on January 25, 2012. She later returned in the show's broadcast on October 23, 2013. Helgenberger received several award nominations for her portrayal of Catherine, including two
Primetime Emmy Award nominations and two
Golden Globe Award nominations.