Billy portrayed Dr. Gilbert “Gil” Grissom on CSI: Crime Scene Investigation for its first 9 seasons.
Grissom was a forensic entomologist and the night shift supervisor at the CSI division of Clark County, Nevada. His characterization of an intelligent, eccentric and intensely private man with an ironic sense of humor received positive responses from critics, ranking Grissom number 82 on Bravo’s list of Greatest Television Characters of All Time. Grissom’s final episode (One to Go) drew over 23 million viewers. Although it was previously confirmed that Grissom would not return to the show as a regular, he made a brief appearance in The Two Mrs Grissoms (season 11), which gave many longtime fans a reason to tune in, if only for one scene.
Gil Grissom was the only child of a middle-class family. His father, who died when he was 9, taught botany. He passed his enthusiasm for natural sciences onto his son, who “played doctor” by performing necropsies on small deceased animals found near his home. Gil’s mother, Betty, who was rendered deaf by Otosclerosis, was responsible for his love of books and literature. Due to his Mother’s disability he became fluent in American Sign Language so he could communicate with her. He spent much of his childhood in solitude, studying the science of life and death.
After earning his B.S in Biology at UCLA, Grissom became the youngest coroner in the history of LA County at 22. He was recruited to the Las Vegas crime lab eight years later, which became the #2 crime lab in the country under his direction. His office is filled with his extensive collections of butterflies, moths and various insects, including a pet tarantula and an embalmed fetal pig (Miss Piggy). He also has a maggot farm and frequents the local “body farm” to study corpses in various states of decomposition. He races cockroaches at conventions, handles stress by riding roller-coasters, enjoys classical music and is a lifelong baseball fan. Grissom is well-read and often quotes Shakespeare and other literary and philosophical figures. Although he is very dedicated to his job and sometimes goes to extremes in his investigations, his unwillingness to engage in office politics often alienates his superiors. He is often perceived as a father figure to his team, but very professional in his work. When asked why he is a CSI he responds, “Because the dead can’t speak for themselves.”
S1: Season one introduces us to Grissom as the newly-appointed head of the crime lab and his team, Catherine Willows, Nick Stokes Greg Sanders and Warrick Brown, who has to deal with the shooting death of rookie Holly Gribbs as a result of his failure to supervise her as she worked a crime scene. Sara Sidle completes the team in the second episode (Cool Change). Paul Milander is introduced as Grissom’s nemesis in two separate episodes (the Pilot and Anonymous). As the characters begin to develop, hints of a past relationship between Grissom and Sara are implied. It becomes clear that Ecklie will become Grissom’s antagonist and his relationship with Brass begins relax. Grissom’s respect for his team’s abilities are put to the test and strengthened as the season progresses. The first season sets the tone of unique and bizarre cases to be found in Las Vegas.
S2: Amid the unusual cases of season two, Grissom meets dominatrix Lady Heather (Slaves of Las Vegas), with whom he becomes intrigued. Detective Jim Brass is featured in an episode about his trouble daughter (Ellie), which gave the viewer new insight into his character. In Identity Crisis Grissom encounters a residing judge that looks exactly like Paul Milander, the elusive serial killer from season one. His investigation reveals the judge’s startling past, resulting in Milander’s staging of his own suicide. Cross Jurisdictions introduces CSI:Miami as Catherine travels to Miami to work a case with Horatio Caine. Grissom’s relationship with Sara is more obvious, although he’s not sure how to cope with it. His hearing loss becomes apparent, ending the season with his ability to continue to perform his job in question.
S3: A suspect uses his wealth and influence to hire Grissom’s mentor, ex-CSI Dr. Gerrard, to observe the workings of Grissom’s team, who uses the team members’ personal problems to discredit their findings in court (The Accused Is Entitled). Lady Heather’s Box marks the return of Lady Heather when Grissom investigates two murders. Catherine’s daughter almost drowns when she is left alone in a sinking car. Catherine’s husband is later found dead from a bullet wound. Greg’s DNA lab explodes due to a team member’s momentary lapse in judgment and evidence is lost in a case (Play with Fire). Subtle hints begin to affirm the relationship between Grissom and Sara. During a murder investigation Catherine discovers that Sam Braun is her father (Inside the Box) and Grissom pursues a surgical solution to his hearing loss.
S4: Grissom returns sporting a new beard and indicates with a wink (to acknowledge Catherine’s buzzing cell phone) that his hearing problem is resolved (Assume Nothing). Sara is deeply affected by a home invasion case (Homebodies), which also presents some intense moments between her and Grissom during the investigation. A comedic departure for Halloween (Fur and Loathing) introduces us to the world of plushies and furries. A nurse with an unsettling resemblance to Sara is found dead in her home (Butterflied). Grissom is prompted to contemplate his workaholic life and the life he may be missing in one of his most revealing interrogation scenes. A serial rapist eludes capture until Grissom discovers his rare genetic condition. Sara is arrested for DUI after losing a promotion to Nick, but Grissom mitigates the situation when she is brought back to the station in Bloodlines.
S5: Greg Sanders finds a replacement for his lab and pursues his goal of becoming a CSI. Down the Drain hints at a relationship between Catherine and Warrick. Ecklie is appointed the new Assistant Director of the crime lab (Formalities) and he pulls Sophia Curtis from day shift to work with Grissom. During a retrial, a formerly invisible fingerprint appears on a matchbook in evidence and Grissom reopens the case (Mea Culpa). Ecklie launches an investigation into Grissom’s past handling of cases with intent to discredit him, and ultimately splits up the team. Greg passes his final proficiency test in (Who Shot Sherlock). The course of the season reveals more of Sara’s past and some of the reasons she is so affected by cases involving domestic and child abuse. In the 2-part season finale directed by Quentin Tarantino (Grave Danger) Nick is kidnapped and buried alive with an explosive device. The team reunites to successfully find Nick. Grissom tells Ecklie he “wants his guys back”.
S6: Season 6 opens with the team reunited after the traumatic events of Nick’s kidnapping. The murder of a man in a garage leads them to the daughter of the man who abducted Nick (Daddy’s Little Girl). Faye Dunaway guest stars as diva called Lois O’Neill, who was related to the mafia years before (Kiss Kiss, Bye Bye). Lady Heather returns and Grissom investigates the death of her estranged daughter in Pirates of the Third Reich. After Brass is shot in a hostage situation, it is revealed that his living will gives Grissom power of attorney, showing that he is the one person Brass trusts with his life. It is revealed to the audience that Grissom and Sara are now in a romantic relationship. (Way to Go).
S7: Grissom discovers the first miniature replica of a crime scene while investigating the murder of a rock star at his home (Built to Kill). Greg witnesses a gang beating someone and after running over one of the attackers to stop the crime he becomes a victim ( Fannysmackin’). Two more mini crime scene replicas are discovered during unrelated murder investigations. Grissom announces that he is going on sabbatical. In Grissom’s absence, Michael Keppler (Liev Schreiber) is brought in to lead the team. When a Trenton cop is murdered in Las Vegas, a secret in Keppler’s past is exposed and he is killed in the resulting investigation (Law of Gravity). Grissom returns to another mini crime scene replica, one that hasn’t yet happened. The season ends with the miniature crime scene killer kidnapping Sara and leaving her injured and stranded under a car in the desert (Living Doll).
S8: The team rescues Sara (Dead Doll) and the miniature crime scene killer is found. Agent Jack Malone (Anthony LaPaglia) from Without a Trace joins Grissom for a child abduction case in Who and What. Grissom proposes to Sara (The Case of the Cross-Dressing Carp). Sara’s investigation of a murder leads her to a former suspect, causing her to question her reasons for continuing her career path. With little warning, she leaves Las Vegas (Good Bye and Good Luck) and her job as a CSI. Warrick’s life begins to fall apart as he struggles with his failing marriage and drug dependency. He is framed for a murder at a local night club in Cockroaches. The team searches for clues in Warrick’s case and Illegal dog fighting is brought to light in Lying Down With Dogs. Warrick is found at the scene of a mobster’s killing with the murder weapon and no recollection of the crime in For Gedda. He is fatally shot in his car after leaving a diner where he met with Grissom and Stokes.
S9: Grissom discovers Warrick’s body in his parked car but Warrick dies before he can name his attacker. Undersheriff McKeen is later apprehended and arrested for framing him. Sara returns and Grissom delivers the eulogy at Warrick’s funeral in For Warrick. Sara leaves CSI for good to do research in Costa Rica. Grissom joins the class of criminal pathologist Dr. Raymond Langston to gain access to a serial killer in order to solve a case (19 Down). Grissom decides to leave the crime lab in the hands of Dr. Langston after the case is solved. In One to Go, after a series of goodbyes to his co-workers, Grissom silently leaves the crime lab and departs for Costa Rica for a reunion with Sara. In his last scene, they are reuniting at her campsite.
In subsequent episodes, Grissom was said to be guest-lecturing and consulting in both France and Peru. As Sara returns to CSI in Season 10 we discover that she and Grissom are married and maintaining a long-distance relationship. As mentioned above, at the end of the season 11 episode The Two Mrs Grissoms, Sara and Grissom’s mother are shown talking with Gil via webcam. Billy returned to CSI for the Series Finale, Immortality in 2015.
Billy’s quotes about Grissom:
“Sometimes I’m just in a haze and I wake up and say to the crew, ‘Refresh my memory, why am I standing in this lab?’ If you see my character carrying a clipboard or staring at a computer, there’s a good chance I’m reading my lines.”
“I was horrible at science and math. I couldn’t pass a test to save my life! I’m surprised that it didn’t take me until I was 20 to graduate. That’s why my role is so cool Grissom is the complete opposite of me!”
“They make me dye my hair darker because it photographs better, but since we shoot out of sequence I walk into a room with it one color and when I leave it’s another.”
“I so love this character of Gil Grissom and I wanted to do this show because it was an opportunity for me to learn stuff. I figured if I could learn stuff, I would be thrilled by the show each week.”
– William Petersen
This page has kindly been re-written by our good friend Ebuzz55 (thanks for proofreading, J).
Sources: Wikipedia, IMDB and the original character biography from the CBS website.