# William Petersen
**William Petersen** (full name William Louis Petersen, born 1953) is an American actor and producer known for his screen roles as Richard Chance in [William Friedkin](https://www.edgepedia.org/william-friedkin)'s *To Live and Die in L.A.* (1985) and Will Graham in [Michael Mann](https://www.edgepedia.org/michael-mann)'s *Manhunter* (1986), and above all as forensic investigator [Gil Grissom](https://www.edgepedia.org/gil-grissom), the original lead of the CBS crime series *CSI: Crime Scene Investigation*.[1](https://www.imdb.com/name/nm0676973) A product of the Chicago stage, where he co-founded the Remains Theater Ensemble, he repeatedly chose theater work and Chicago life over Hollywood career building, and became a major television star only after the role for which he is now best known.[2](https://www.tvinsider.com/people/william-petersen/)
| Key fact | Detail |
|---|---|
| Born | 1953, Evanston, Illinois; youngest of six children in a Danish and German heritage family of furniture retailers[3](https://billypetersen.com/billy-bio/) |
| Signature roles | Richard Chance in *To Live and Die in L.A.* (1985); Will Graham in *Manhunter* (1986); Gil Grissom in *CSI* (2000–15)[1](https://www.imdb.com/name/nm0676973) |
| CSI tenure | Starred for nine seasons and served as executive producer; announced his departure in 2008, returned for the 2015 two-hour series finale[2](https://www.tvinsider.com/people/william-petersen/) • [4](https://time.com/3963577/csi-finale-marg-helgenberger-william-petersen/) |
| Theater roots | Co-founded the Remains Theater Ensemble in Chicago in 1979 with Gary Cole and Ted Levine; Joseph Jefferson Award for *In the Belly of the Beast*[5](https://www.dailyactor.com/news/biography-william-petersen/) • [6](https://cinema.com/people/001/960/william-petersen/) |
| Steppenwolf | Became the 42nd member of the Steppenwolf Theatre Company ensemble in December 2008[7](https://billypetersen.com/2008/12/billy-joins-the-steppenwolf-ensemble/) |
| Television honors | 2005 Screen Actors Guild Award for ensemble in a drama series; Golden Globe nomination; 2001 Alan J. Pakula Award[8](https://www.tvguide.com/celebrities/william-petersen/bio/3000184937/) |
| Family | Married Gina Cirone in 2003; daughter Maite born 1975 to first wife Joanne Brady, and twins born 2011[3](https://billypetersen.com/billy-bio/) |
## Early life and the Chicago stage
Petersen grew up in [Evanston, Illinois](https://www.edgepedia.org/evanston-illinois), outside Chicago, and moved to [Boise, Idaho](https://www.edgepedia.org/boise-idaho), at 15 to live with an older brother. He graduated from Bishop Kelly High School in 1972 and enrolled at Idaho State University in Pocatello on a football scholarship.[3](https://billypetersen.com/billy-bio/) • [8](https://www.tvguide.com/celebrities/william-petersen/bio/3000184937/) His grades fell below the level required to play, so the university placed him in theater stagecraft classes to raise his grade point average; he fell in love with the theater.[3](https://billypetersen.com/billy-bio/) He and his first wife followed a favorite professor to Spain, where they started a Shakespeare company in the Basque region; Petersen learned the [Basque language](https://www.edgepedia.org/basque-language) and later gave his firstborn child a Basque name.[9](https://biographs.org/william-petersen)
Back in the United States he worked, among other jobs, as a logger in northern Idaho before loading his family into a car and driving to Chicago to try acting full time.[10](https://steppenwolf.buzzsprout.com/961903/episodes/3810653-ep4-william-petersen-cast-me-or-not) He earned his Actors' Equity card in 1978 at the Victory Gardens Theater in the title role of *Dillinger*, shaving his head to resemble the gangster's hairline, and in 1979 founded the Remains Theater Ensemble with fellow actors including [Gary Cole](https://www.edgepedia.org/gary-cole) and [Ted Levine](https://www.edgepedia.org/ted-levine).[5](https://www.dailyactor.com/news/biography-william-petersen/) • [11](https://billypetersen.com/extras/magazine-transcripts/chicago-magazine-1998/) Remains produced experimental work and made Petersen a fixture of the off-Loop scene; after financial difficulties and the death of co-artistic director Larry Sloan, the company disbanded in 1995.[3](https://billypetersen.com/billy-bio/)
His breakthrough stage role was Jack Henry Abbott, the convicted killer and author, in *In the Belly of the Beast: Letters from Prison*, first performed in 1983 at the Wisdom Bridge Theatre in Chicago and later taken to the Edinburgh Festival and the Kennedy Center.[5](https://www.dailyactor.com/news/biography-william-petersen/) The performance won him a Joseph Jefferson Award, Chicago's top theater honor, and [Chicago Tribune](https://www.edgepedia.org/chicago-tribune) critic Richard Christiansen later ranked it among his ten greatest theater experiences after four decades of reviewing.[12](https://billypetersen.com/career/)
## Film breakthrough and the road not taken
William Friedkin saw Petersen performing in *A Streetcar Named Desire* at the [Stratford Festival](https://www.edgepedia.org/stratford-festival) in Ontario and cast him on the spot in *To Live and Die in L.A.* (1985), his first starring film role, as a Secret Service agent pursuing a counterfeiter.[3](https://billypetersen.com/billy-bio/) • [11](https://billypetersen.com/extras/magazine-transcripts/chicago-magazine-1998/) The following year he played FBI profiler Will Graham in Michael Mann's *Manhunter*, the first screen adaptation of [Thomas Harris](https://www.edgepedia.org/thomas-harris)'s *Red Dragon* and the film that introduced [Hannibal Lecter](https://www.edgepedia.org/hannibal-lecter) to movie audiences.[13](https://www.latimes.com/archives/la-xpm-1992-06-07-tv-430-story.html) *Rolling Stone* touted him as the hot actor of the summer of 1986, but *Manhunter* failed at the box office.[13](https://www.latimes.com/archives/la-xpm-1992-06-07-tv-430-story.html)
Subsequent features, including *Amazing Grace and Chuck*, *Cousins*, *Hard Promises*, and *Passed Away*, fared poorly to moderately, and Petersen never became the movie star early reviews predicted.[13](https://www.latimes.com/archives/la-xpm-1992-06-07-tv-430-story.html) The choices were partly his own: he turned down a part in [Oliver Stone](https://www.edgepedia.org/oliver-stone)'s *Platoon* (1986) because he did not want to be away from his family for six weeks, and declined the role of [Henry Hill](https://www.edgepedia.org/henry-hill) in Martin Scorsese's *Goodfellas*.[2](https://www.tvinsider.com/people/william-petersen/) In 1990 he and producer Cindy Chvatal founded High Horse Films, whose first production was *Hard Promises*.[3](https://billypetersen.com/billy-bio/)
## CSI: Crime Scene Investigation
In 2000 Petersen was cast as Gil Grissom, a forensic entomologist who leads a Las Vegas crime-scene investigation team, in *CSI: Crime Scene Investigation*, on which he also served as an executive producer from the first episode.[2](https://www.tvinsider.com/people/william-petersen/) • [1](https://www.imdb.com/name/nm0676973) The series became a top-rated hit and spawned a franchise, and it made Petersen a household name; he later told a [United States Senate](https://www.edgepedia.org/united-states-senate) hearing that preparing for the role had drawn him into the field of forensic science.[14](https://www.govinfo.gov/content/pkg/CHRG-107shrg78008/pdf/CHRG-107shrg78008.pdf)
The role brought ensemble and individual recognition: a Golden Globe nomination, Primetime Emmy nominations for the series as Outstanding Drama Series, shared Producers Guild nominations, and a 2005 Screen Actors Guild Award shared with his fellow cast members for Outstanding Performance by an Ensemble in a Drama Series.[8](https://www.tvguide.com/celebrities/william-petersen/bio/3000184937/) In 2008 he announced he would leave the series to return to stage acting, saying he felt he was beginning to atrophy as a performer; his final episode as a regular drew 23 million viewers.[2](https://www.tvinsider.com/people/william-petersen/) He remained an executive producer on the show and returned with Marg Helgenberger for the two-hour series finale broadcast on September 27, 2015.[4](https://time.com/3963577/csi-finale-marg-helgenberger-william-petersen/)
## Later career
After leaving *CSI* Petersen re-committed to Chicago theater. In December 2008 he joined the Steppenwolf Theatre Company as the 42nd member of its acting ensemble, starring there in *Dublin Carol* and later appearing in *Endgame*, *Slowgirl* at the Geffen Playhouse in Los Angeles, and *The Minutes*.[7](https://billypetersen.com/2008/12/billy-joins-the-steppenwolf-ensemble/) • [10](https://steppenwolf.buzzsprout.com/961903/episodes/3810653-ep4-william-petersen-cast-me-or-not) In 2009 he received a star on the Hollywood Walk of Fame at 6667 Hollywood Blvd, and that same year won his third Joseph Jefferson Award for *Blackbird* at Chicago's Victory Gardens Theater.[2](https://www.tvinsider.com/people/william-petersen/) • [8](https://www.tvguide.com/celebrities/william-petersen/bio/3000184937/)
Television work continued intermittently. He played Joseph P. Kennedy in the 1990 miniseries *The Kennedys of Massachusetts* and his son John F. Kennedy in HBO's *The Rat Pack*, starred in the WGN series *Manhattan* as Colonel Emmett Darrow (2014–15), and appeared in the films *Detachment* (2011) and *Seeking a Friend for the End of the World* (2012).[2](https://www.tvinsider.com/people/william-petersen/) • [1](https://www.imdb.com/name/nm0676973) In 2021 he reprised Gil Grissom alongside Jorja Fox's Sara Sidle in the revival *CSI: Vegas*, appearing in all ten episodes of the first season and serving as executive producer.[2](https://www.tvinsider.com/people/william-petersen/) He fell ill on set during production and was hospitalized, did not return for the second season, and by late 2025 interviews reported him as publicly retired from acting.[2](https://www.tvinsider.com/people/william-petersen/) • [15](https://shop.bottegadelsarto.com/opinion/william-petersen-2026-update-238472)
## Personal life
Petersen married Joanne Brady in the mid-1970s; their daughter Maite was born in 1975, and the marriage ended in divorce in 1981.[3](https://billypetersen.com/billy-bio/) He married Gina Cirone, a biology teacher, in 2003, and their twins were born in 2011.[3](https://billypetersen.com/billy-bio/) He has kept a deliberately low public profile: he maintains no verified social media accounts, and profiles describe a preference for Chicago, where he is an avid Cubs fan, over the Los Angeles entertainment industry.[3](https://billypetersen.com/billy-bio/) • [16](https://www.wbez.org/2008/10/29/chicago-treasures-bill-petersen)
## Other people named William Petersen
The name is shared by several unrelated figures. William L. Petersen (1882–1968) was a Minnesota attorney who served as a nonpartisan state senator for District 67 from 1931 to 1935.[17](https://mn.electionarchives.lib.umn.edu/candidate/william-l-petersen/) William Petersen is also the name of a sociologist whose chapter "Politics and the Measurement of Ethnicity" appeared in *The Politics of Numbers* (1987),[18](https://www.nber.org/system/files/working_papers/w23827/w23827.pdf) of Francis William Petersen, a South African engineer and board chairman of the Council for Scientific and Industrial Research,[19](https://www.unlimitedgroup.co.za/ABRIDGED%20CURRICULUM%20VITAE.pdf) and of William B. Petersen, an atmospheric modeling researcher whose publications are concentrated in air-quality and environmental fields.[20](https://www.rankless.org/authors/william-b-petersen)
## References
1. [William Petersen, IMDb](https://www.imdb.com/name/nm0676973)
2. [William Petersen – Actor, Producer, TV Insider](https://www.tvinsider.com/people/william-petersen/)
3. [Billy Bio, The William Petersen Appreciation Page](https://billypetersen.com/billy-bio/)
4. [*CSI* Finale to Reunite Marg Helgenberger and William Petersen, Time](https://time.com/3963577/csi-finale-marg-helgenberger-william-petersen/)
5. [Biography: William Petersen, Daily Actor](https://www.dailyactor.com/news/biography-william-petersen/)
6. [William Petersen, Cinema.com](https://cinema.com/people/001/960/william-petersen/)
7. [Billy joins the Steppenwolf Ensemble, The William Petersen Appreciation Page](https://billypetersen.com/2008/12/billy-joins-the-steppenwolf-ensemble/)
8. [William Petersen Biography, TV Guide](https://www.tvguide.com/celebrities/william-petersen/bio/3000184937/)
9. [William Petersen biography, Biographs.org](https://biographs.org/william-petersen)
10. [Ep4 – William Petersen: "Cast Me or Not", Steppenwolf podcast](https://steppenwolf.buzzsprout.com/961903/episodes/3810653-ep4-william-petersen-cast-me-or-not)
11. [Chicago Magazine – 1998, The William Petersen Appreciation Page](https://billypetersen.com/extras/magazine-transcripts/chicago-magazine-1998/)
12. [Career, The William Petersen Appreciation Page](https://billypetersen.com/career/)
13. [The Petersen Puzzle, Los Angeles Times (1992)](https://www.latimes.com/archives/la-xpm-1992-06-07-tv-430-story.html)
14. [Statement of William Petersen, U.S. Senate hearing record, govinfo](https://www.govinfo.gov/content/pkg/CHRG-107shrg78008/pdf/CHRG-107shrg78008.pdf)
15. [William Petersen 2026 update](https://shop.bottegadelsarto.com/opinion/william-petersen-2026-update-238472)
16. [Chicago Treasures: Bill Petersen, WBEZ](https://www.wbez.org/2008/10/29/chicago-treasures-bill-petersen)
17. [William L. Petersen, Minnesota Historical Election Archive](https://mn.electionarchives.lib.umn.edu/candidate/william-l-petersen/)
18. [Petersen, William. 1987. "Politics and the Measurement of Ethnicity," in *The Politics of Numbers*](https://www.nber.org/system/files/working_papers/w23827/w23827.pdf)
19. [Abridged Curriculum Vitae, Francis William Petersen](https://www.unlimitedgroup.co.za/ABRIDGED%20CURRICULUM%20VITAE.pdf)
20. [William B. Petersen, Rankless author profile](https://www.rankless.org/authors/william-b-petersen)
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*Topic: Encyclopedia › Arts and culture › Screen and stage › Film and television › Screen people and creators › Screen actors of the Anglosphere and Europe › American actors: 2000s onward › Surnames P to Ph*
*Initially written Sep 17, 2026 · Reviewed: Oct 25, 2026 · Edited: Oct 12, 2026; Oct 15, 2026; Oct 25, 2026 · Last review: Oct 25, 2026*
*Copyright 2026 EdgeChat AI, a subsidiary of Biostate AI.*
License: Edgepedia Community License 1.0, https://www.edgepedia.org/edgepedia/license