Grissom appears to have both moral and intellectual stakes in working as a criminalist. While he rarely, if ever, becomes emotionally involved in cases, he oftenmakes pithy indictments or offers pointed quotations to illustrate his reaction. He was raised Roman Catholic, but he now seems to be a lapsed Catholic. He describes this as "practic[ing] a kind of secular Catholicism that involves ritualizing certain aspects of everyday life and imbuing them with a spiritual intensity they might not otherwise possess". This appears to neatly sum up his personalfaith in scientific rigor as well as humanity, despite the crime scenes he attends every night. In an eighth season crossover arc, he confesses to FBI Agent Jack Malone that he thinks about "hanging them up" every day, but that he has "his pig" - in other words, the work still holds unanswered questions and fresh insights for him. Shortly thereafter, he agrees with colleague David Hodges'description of the work as "a puzzle" that he's not yet ready to let go.
Grissom describes himself as "a ghost" in school, focussing on his studies and on his scientific interests. He was known to pick up and dissect animals killed along the highway, and was eventually called upon to assist local law enforcement with necroscopies and other forensic tasks. (It is hinted in the second season that Grissomhas Asperger's Syndrome, or Asperger's-like tendencies, and these are key examples: social withdrawal and intellectual obsession leading to mastery of a subject.)
Grissom has a degree from UCLA in Biology, and completed his PhD at UC Berkeley. He enjoys teaching, perhaps in part because it provides him with a structured social setting in which he can find success through sharing his interests.He later take a professorial role with his crew, mentoring them through their career developments and imparting wisdoms gleaned from years of experience. As the crew draws near his level of expertise, he finds himself excited to be offered a teaching sabbatical, explaining: "I'm a teacher without any students."
At only 22, Grissom became the youngest country coroner in California history.Winning a surprise windfall in a college poker game, he set up his first Body Farm - a natural setting where donated human bodies could be observed and recorded at all stages of the process of decomposition, local predation, and of course, bugs - entomological interference.
At 29, Grissom switched careers and became a CSI, rising quickly through the ranks to become a shift supervisor. He eventuallytransferred from the San Francisco PD to the Las Vegas PD, and took over the graveyard shift. Under his guidance, the LVPD Crime Lab rose to a second place crime-solving position in the country, second only to the well-funded FBI national headquarters at Quantico.
Grissom, while attached mainly to his work, does make friendly connections with his staff. And at least one friend is willing torelocate entirely to work with him: CSI Sara Sidle appears in the second episode of the series, called in from San Francisco by Grissom to run an internal investigation. His night shift crew treat him as an avuncular figure, eccentric but wise, hilariously dry, and solid as a rock. His own supervisor, Conrad Ecklie, considers him the proverbial thorn and a possible contender, and takes everyopportunity to put him in his place.
Grissom's inherited his mother's otosclerosis, a fusion of the small bones in the ear, which nearly led to the loss of his hearing. This leads him even further into himself, withdrawing emotionally from his crew, and especially from Sara, for whom he has feelings he can neither deny nor act upon. With successful surgery, he regains his full hearing, but the...