Gil Grissom
Dr. Gilbert "Gil" Grissom, Ph.D., is a fictional character on the CBS crime drama CSI: Crime Scene Investigation, portrayed by William Petersen. Grissom was a forensic entomologist and the night-shift supervisor of the Clark County, Nevada CSI (forensics) team, investigating crimes in and around the city of Las Vegas. He was the show's protagonist from seasons 1 to 9, when Petersen left the show as a regular, and was replaced by Laurence Fishburne as Dr. Raymond Langston, M.D..
CSI: Crime Scene Investigation producer and writer Carol Mendelsohn considers Grissom the center of the show, and in the first seven years of the show he appeared in every episode, with the exception of "Hollywood Brass", from season five, "Gum Drops" and "The Unusual Suspect" from season six, and "Sweet Jane" and "Redrum" from season seven. In late season 6 it is revealed that he has become romantically involved with subordinate CSI Sara Sidle.
Grissom has received positive responses from critics, ranking number 82 on Bravo's 100 Greatest TV Characters list, along with Catherine Willows. Grissom's final episode as a regular drew over 23 million viewers.
Although Petersen has confirmed that Grissom will not return to the show as a regular, he did reprise his role for an uncredited appearance in the season eleven episode "The Two Mrs. Grissoms." This return was kept secret until CTV accidentally leaked the promo; since then, most copies have been pulled.
Read more about Gil Grissom: Creation and Development, Appearances, Parallelism With Sherlock Holmes, Relationships With Other Characters