Main Character: Las Vegas
William Petersen
Name Gilbert Arthur "Gil' Grissom
Gender Male
Birth Date August 17, 1956
Family Sara Sidle (wife)
Betty Grissom (mother)
Unnamed father
City Las Vegas
Job Night shift supervisor (formerly)
Rank CSI Level 3
Specialty Entomology
Status Alive/Retired (2021)
Portrayed By William Petersen

Gilbert Arthur "Gil" Grissom is the former night shift supervisor at the Las Vegas Crime Lab.

He quit his job to fly out to Costa Rica to reunite with his fiancée and former subordinate, Sara Sidle (One To Go). They subsequently got married. Sara has returned to the Crime Lab, but later left to be with Grissom in his boat while he works to preserve sharks in international waters ("Immortality')


Grissom's dispassionate demeanor and high intellect often work to his advantage in his job, though it is strongly hinted, especially in the early seasons, that it takes its toll on his personal life. Grissom is rarely disturbed by the various subcultures with which his job brings him into contact, but it frequently makes him insensitive and lacking empathy towards other people—it is clearly notable that he is somewhat out of touch of the human part of his job, which is a frequent point of argument between him and fellow colleague Catherine Willows.

He hates abusive husbands, child predators, and drug dealers who "deal death to kids" (Friends & Lovers).

Grissom is the least trigger—happy CSI, rarely drawing his firearm, a tendency that has brought about several scoldings from friend and cop Jim Brass.[citation needed]

He was raised Roman Catholic, but has said, "That guilt's not a part of my life."[1] Also when speaking with a priest who heard the confession of a murderer he said "I believe in science, and I believe in God, but I don't believe in someone telling me how to live my life" (Alter Boys). He later tells Sara Sidle that, while he isn't really a Catholic anymore, he is a sort of "secular Catholic" who infuses his work with more meaning than it might otherwise have (Double Cross). He also continues to believe in God, as he tells her he believes both science and faith are necessary. He keeps his mother's rosary beads in a box in his office.[citation needed]

His avoidance of job politics (and paperwork) often alienates his superiors (and sometimes his subordinates), and right—hand woman Catherine Willows occasionally has to prod him to perform such menial tasks as employee evaluations (Evaluation Day).

Grissom's hobbies include his work, cockroach racing, reading, solving crossword puzzles, and riding roller coasters (Evaluation Day). Gil is prone to migraines when under extreme stress, which he usually addresses by turning the lights down, closing his eyes, and lying down on a couch.[2]

One of the most notable parts of his personality includes his difficult in relating to other people, especially on an emotional level. In Chaos Theory, he becomes lost in thought while listening to a victim's parents to the point he's no longer hearing them. He is attracted to several women over the years, including colleagues, subordinates, and suspects, but seems to want to keep them away more than he wants to connect with them.[3] During the early seasons, it was suggested that Grissom is a helpless bachelor; when Catherine visited him in his condo while suspended, a book titled "Single After 50" is clearly visible on his bookshelf (Strip Strangler).

Early Life[]

Grissom was born on August 17, 1956, in Santa Monica, California.[4] He grew up in Marina Del Rey, California (The Theory of Everything). His mother ran an art gallery in Venice. She went deaf shortly after his birth from osteosclerosis.[5] His father was in the importing/exporting business. He also taught botany at a local college and died when Grissom was nine years old, most likely from heat stroke (Still Life). His hobbies as a child included ant farming and performing autopsies on roadkill.[6] He says that in high school, he was a "ghost" (Bully for You). He earned a PhD in Biology from UCLA at the age of twenty—two.[7] He was mentored in criminalistics by Dr. Philip Gerard (The Accused is Entitled). He also spent time learning in some unorthodox ways, such as observing live blood spatter and bruise formations at boxing matches (Fight Night) or financing a body farm with his poker winnings (Revenge is Best Served Cold).


Season One[]

In Pilot, a new recruit called Holly Gribbs is shot while she is analyzing a crime scene. This causes current Night Shift Supervisor Jim Brass to be demoted from his postion and it allows Grissom to become the new Night Shift Supervisor. Grissom also works on a case which involves a staged suicide, which leads him to believe a serial killer is on the loose after he kills again.

He recruits Sara Sidle as Holly's new replacement in the lab. Grissom settles into his new role well however he comes into conflict with Conrad Ecklie and Sheriff Brian Mobley over political issues with cases.

Grissom also comes into contact with another serial killer called The Strip Strangler, whom Grissom attempts to capture. After following many leads, he goes to the serial killer's apartment complex alone, which ends in the serial killer almost killing Grissom before Catherine Willows shoots him in the chest before he can kill Grissom.

Season Two[]

At the end of The Hunger Artist, we discover that Grissom is losing his hearing from a degenerative disease, Otosclerosis, that he inherits from his mother. 

Season Three[]

In the season finale Inside the Box , Grissom undergoes a corrective surgery to restore his hearing, which was proven successful in the season four premiere, Assume Nothing.

Season Four[]

Grissom is back after the surgery, observant like in previous seasons, but now he is bearded.

Season Five[]

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Season Six[]

In this season finale it is revealed his affair with Sara, and while in bed, he says:

"I don't know. Most people want to die in their sleep, I suppose. Never know that it's happening, like a crime scene. Surprise, you're dead. I'd prefer to know in advance that I was going to die. I'd like to be diagnosed with cancer actually, have some time to prepare. Go back to the rain forest one more time, reread 'Moby Dick. Possibly enter an international chess tournament. At least have enough time to say 'goodbye' to the ones that I love."

Season Seven[]

A package is delivered to Grissom's desk, after he had already left for his sabbatical (Leaving Las Vegas). It waits there with his accumulating mail until he finally returns a month later and opens it (Monster in the Box). He is shocked to discover a perfect scale miniature of the scene of a crime—one that has not happened yet. He and the rest of his team had thought that they had caught the so—called Miniature Killer (Built to Kill, Part 2, Post Mortem). They are left with no real leads and far more questions than answers.

In 2007, Grissom took a sabbatical to teach a class at Williams College in Williamstown, Massachusetts for four weeks (Leaving Las Vegas). Prior to his sabbatical, Grissom had been showing signs of "burnout". Upon his return, however, he appears reinvigorated and imparts to Warrick Brown that he "missed Las Vegas" (Law of Gravity).

Season Eight[]

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Season Nine[]

After being shot by Undersherriff McKeen, Warrick dies in Grissom's arms (For Warrick). After the funeral, Sara leaves the team for good, and breaks up with Grissom, leaving him desperate (Leave Out All The Rest). He then decides to leave the crime lab (19 Down...), and goes to find Sara in Costa Rica (One to Go). 

A flashback shows Grissom leaving Nick a message wishing him happy birthday (Turn, Turn, Turn). In the message, Grissom mentions testifying about decapitation by blown tire, referring to the second episode of the eight season (A La Cart).

Season Eleven[]

Grissom made a brief appearance on a video call with Sara and his mother, Betty Grissom, at the end of The Two Mrs. Grissoms.


Grissom now works to preserve sharks in the oceans, and on the beginning of the movie he is arrested for trespassing at the port of San Diego. He is released on the request of Conrad Ecklie, who needs his assistance at the lab, to work a case that may involve Lady Heather.

During the movie, in several occasions it is shown that he still have feelings for Sara, the most evident moment is when he states to Lady Heather that Sara made him have faith in humankind again, saying that he'll be missing her.

He congratulates her for being promoted and leave to his boat, and is later rejoined by Sara.


In so much as Grissom confides to anyone, he confides in Catherine Willows. He once likened her to being his "wife" though the two have never been more than very good friends. Grissom has also been involved with forensic anthropologist Teri Miller (To Halve and to Hold) and S&M parlor operator Lady Heather. He has supported Warrick Brown through several brushes with the law and has a fatherly bond with Nick Stokes and, later on, Greg Sanders. He also shares a good friendship with Dr. Al Robbins.

Of all of his fellow investigators, he is closest to Sara Sidle. Both are self—described "science nerds" and are the most socially awkward members of the team. While at times both have expressed more than a hint of interest in the other romantically, it is not until the sixth season finale that they are definitely shown to be involved. In seventh season episodes, he continues to be involved with Sara Sidle, but is keeping the relationship a secret from others in the lab, probably because of the repercussions it could have for both their careers. Grissom trusts Sara intimately (Fallen Idols).

Grissom proposed to Sara in Season 8, and they were married between Seasons 9 and 10. In Season 13, episode Forget Me Not, they have been separated for a while. They eventually got together again in "Immortality"


CSI:Crime Scene Investigation
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 #
Season 1 X X X X X X X X X X X X X X X X X X X X X X X N/A 23
Season 2 X X X X X X X X X X X X X X X X X X X X X X X N/A 23
Season 3 X X X X X X X X X X X X X X X X X X X X X X X N/A 23
Season 4 X X X X X X X X X X X X X X X X X X X X X X X N/A 23
Season 5 X X X X X X X X X X X X X X X X X X X - X X X X X 24
Season 6 X X X X - X X X X X X X X X X X X - X X X X X X N/A 22
Season 7 X X X X X X X X X X X - - X X X X X X X X X X X N/A 22
Season 8 X X X X X X X X X X X X X X X X X N/A 17
Season 9 X X X X X X X X X X - - - - - X - - - - - - - - N/A 11
Season 11 - - - - - - - - - - - - X - - - - - - - - - N/A 1
Season 13 - - X - - - - - - - X - - - - - - - - - - - N/A 2
Season 15 - - - - - - - - - - - - - - - - - - X X N/A 2
Total 193
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 #
Season 1 X X X X X X X X X X N/A 10
Total 10


  • It was said, in Double Cross, that Gil Grissom is a Catholic or perhaps was in the past.
  • The character was originally intended to be named Gil Scheinbaum. According to William Petersen, interviewed for UK TV channel Five US, Petersen was considered 'insufficiently Jewish' by series creator Anthony E. Zuiker for the name and the character was renamed for astronaut Gus Grissom. [citation needed]
  • Despite the Grissom character being from the West Coast, he has a somewhat noticeable Chicago accent. For instance, he pronounces Nevada as nəˈvɑda. [citation needed] (Petersen is from the Chicago area.) [citation needed]
  • He keeps a variety of specimens in his office, including a radiated fetal pig and a tarantula. He also has a fish—shaped bulletin board on which unsolved cases go: "the ones that got away" (Who Are You?). In keeping with the fish theme, he has a Big Mouth Billy Bass over the door to his office, claiming that it's "better than a watchdog."
  • Grissom is based loosely on real life Las Vegas Metropolitan Police Department criminalist Daniel Holstein.[citation needed]
  • Grissom has similarities with Sherlock Holmes.[citation needed]
  • At the start of Season Seven, Grissom shaves his beard for the first time in three seasons, but he has the beard again upon return from his sabbatical. However, Sara Sidle later is about to shave Grissom (Fallen Idols).
  • Enjoys riding roller coasters every year when he completes his evaluations of the CSI staff. [citation needed]
  • Most people call Grissom by his last name, though Catherine Willows, Dr. Al Robbins, and Conrad Ecklie (David Phillips and David Hodges in Season 9, episode 4) will address him as "Gil," and Warrick Brown uses the shortened form "Griss.". And also in 'Under a Cloud', Nick Stokes calls him "Griss". On a few occasions, Grissom has been known by the nickname "Bugman". [citation needed]
  • Grissom identifies himself as "Gil" when he refers to himself on the phone (Room Service).
  • Grissom inherited his mother's otosclerosis, a disease which was causing him to slowly go deaf. His hearing loss becomes increasingly evident over time (Chaos Theory), but he underwent corrective surgery (Inside the Box).
  • Grissom gets an occasional migraine (which he claims he gets about once a year), for which he has prescription medication. [citation needed]
  • When asked why he is a CSI, he frequently responds, "Because the dead can't speak for themselves." (Toe Tags).
  • Briefly noted and unclassified, Grissom felt a likeness to Aaron Pratt, and autistic curator. Speculation leads, from Nick's brief comment about Aaron's abilities, that "he's just like you, Grissom". (Caged) This leads some to belief Grissom is a functioning autistic adult.


  • Grissom is extremely knowledgeable about literature, in particular the Sherlock Holmes stories and novels. He occasionally quotes Shakespeare and has a weakness for wordplay and slightly off—color puns.
  • Grissom has extensive knowledge about entomology. The character of Will Graham whom William Petersen played in the film Manhunter (based upon the Thomas Harris novel Red Dragon), wrote "the standard monograph on determining time of death by insect activity".
  • In Seasons 1 and 2 he used a Glock 17 but then stopped carrying in Season 3


  1. "Altar Boys", Season 2 Episode 6
  2. He got one after being suspended in Strip Strangler, and again after closing a murder by a pedophile in Burn Out.
  3. Flaherty, M. & Marrinan, C. (2004). CSI: Crime scene investigation companion. New York, NY: Pocket Books.
  4. Grissom states this while investigating Paul Millander in Identity Crisis.
  5. Flaherty, M. & Marrinan, C. (2004). CSI: Crime scene investigation companion. New York, NY: Pocket Books.
  6. Flaherty, M. & Marrinan, C. (2004). CSI: Crime scene investigation companion. New York, NY: Pocket Books.
  7. Flaherty, M. & Marrinan, C. (2004). CSI: Crime scene investigation companion. New York, NY: Pocket Books.