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 4) a case of raccoon versus big rig ("Fur and Loathing"), a car-bombing ("Grissom Versus the Volcano"), and the derailment of a roller-coaster ("Turn of the Screws"). Meanwhile, Catherine usurps a case from Nick and Sara ("After the Show"), the team have to re-investigate a rape-murder ("Invisible Evidence"), Grissom heads to Jackpot, Nevada ("Jackpot"), and team take part in a CSI relay, bringing together investigative teams from across America ("Dead Ringer"). <onlyinclude> </onlyinclude> CSI: Crime Scene Investigation (season 4) The fourth season of "" premiered on CBS on September 25, 2003 and ended May 20, 2004. The series stars William Petersen