CSI: Crime Scene Investigation physical evidence to solve murders. The team is originally led by Gil Grissom (Petersen), a socially awkward forensic entomologist and career criminalist who is promoted to CSI supervisor following the death of a trainee investigator. Grissom's second-in-command, Catherine Willows (Marg Helgenberger), is a single mother with a cop's instinct. Born and raised in Las Vegas, Catherine was a stripper before being recruited into law enforcement and training as a blood-spatter specialist. Following Grissom's departure during the ninth season of the series, Catherine is promoted to supervisor. After overseeing the training of new investigator Raymond Langston (Fishburne), Willows is replaced by
CSI: Crime Scene Investigation (season 9) CSI: Crime Scene Investigation (season 9) The ninth season of "" premiered on CBS on October 9, 2008 and ended May 14, 2009. The series stars William Petersen, Marg Helgenberger and Laurence Fishburne. As the team grieve for their fallen colleague ("For Warrick"), Grissom makes a life changing decision ("One to Go"), during the ninth season of "CSI". Also this season, Sara investigates the death of a woman attacked nine years ago ("The Happy Place"), new CSI Riley Adams joins the team ("Art Imitates Life"), and she and Nick witness a store robbery on Halloween ("Let it Bleed"), Grissom attends