William Petersen as Gil Grissom
Born: February 21, 1953
Birthplace: Evanston, IL
Marital Status: 1st marriage: Joanne; daughter, Matie (b. 1975). 2nd marriage, Gina Cirone (m Jun 14 2003)
Credits: Please check out the IMDB Database

William was the youngest of six children born to a family in Evanston, Illinois. While he excelled at sports, his academic grades were poor, so while at Idaho State University his advisors recommended he take acting classes in order to boost his grade point average. Little did they know that William would flourish in the theatrical atmosphere, so much so that after he left school, William and Joanne (his girlfriend who soon became his wife) went to Spain where they started a Shakespeare company. Soon he and his wife (and new daughter) moved back to Evanston, where he dabbled in other jobs, but the lure of the theater took him to Chicago where he earned his Actor's Equity card in 1979 at the Victory Gardens Theater. With longtime friend Cindy Chvatal and actor Gary Cole, they co-founded the Remains Theater, where Petersen honed his acting abilities. His portrayal of Jack Henry Abbott in Belly of the Beast: Letters from Prison earned his the Joseph Jefferson award for best actor, which he reprised at the Kennedy Center and in London. He also received Joseph Jefferson Award nominations for The Tooth of the Crime and The Night of the Iguana. He appeared in a number of regional productions, including The Time of Your Life, A Streetcar Named Desire, Glengarry Glen Ross, Fool for Love and Speed-the-Plow. His Broadway debuted was in a revival of Tennessee Williams' Night of the Iguana.

His talent soon came to the attention of film directors, and he was asked to read for William Friedkin's cop thriller, To Live and Die in L.A. That film led to more, such as Manhunter, Cousins and Fear. In 1990, William and Cindy Chvatal formed High Horse Films. Their first project was Hard Promises, in which William starred with Sissy Spacek.

On television, he has been seen in Long Gone, The Rat Pack, , 12 Angry Men, The Kennedys of Massachusetts (which won a Golden Globe Award), the sci-fi miniseries The Beast and Keep the Change, which he also produced. It was only when CSI came along that Petersen decided to commit to his first television series, which he also produces.

Petersen resides with his wife in Los Angeles, and became a grandfather for the first time in October 2003.

For more information, check out the William Petersen - The Early Years and Charlie Rose transcript as well.

Also credited as William L. Petersen (full name William Louis Petersen)

Marg Helgenberger as Catherine Willows
Born: November 16, 1958
Birthplace: Fremont, NE
Marital Status: Married (1989), actor Alan Rosenberg, son Hugh (b. 1990)
Credits: Please check out the IMDB Database

Marg Helgenberger is known to many TV viewers from her Emmy award-winning performance as K.C. from the ABC series China Beach. Born in Nebraska to Hugh (who worked in a meat packing plant) and Kay (a nurse) Helgenberger, Mary Margaret Helgenberger didn't discover acting until after she graduated high school. During those years, she was active in extracurricular activities, and spent her summer vacations working as a "boner" (a person who strips meat off the bones) at a meat packing plant. Marg attended Kearney State College, then transferred to Northwestern Alumnus School of Speech, where she majored in Speech and Drama. It was during a university production of A Streetcar Named Desire that Marg got hooked on acting.

A scout for the soap opera Ryan's Hope saw Marg perform during a campus production of Taming of the Shrew, then offered her a possible role on the show. Marg, however, wanted to finish college first and joined the soap as Siobhan Ryan. It was in 1984 when actor Alan Rosenberg did a guest spot on the soap as a pimp. He caught her eye, but they lost contact until they ran into each other at a bank in West Hollywood. They began dating, and married in 1989. In 1990 they had a son, Hughie, whom they named in honor of her late father.

Marg is best known for China Beach, but her other TV credits include ER, the telemovie Perfect Murder, Perfect Town, Thanks of a Grateful Nation, and the Stephen King mini-series The Tommyknockers. She appeared in the critically acclaimed Erin Brockovich with Julia Roberts, Species, Species II, Fire Down Below, The Last Time I Committed Suicide, Crooked Hearts, and more.

Marg has received the Q Award from the Viewers for Quality Television for three years during her time on China Beach. She has also received nominations for Outstanding Lead Actress in a Drama Series in 2001 and 2001, and when someone appears on the talk show circuit to promote CSI, you'll usually find Marg's cheerful face in front of the camera.

Marg is active in speaking out for breast cancer prevention - as her mother is a decades-long survivor of the disease - and each year returns to Council Bluffs, Iowa to host Marg & Alan's Celebrity Weekend, to reconnect with her Midwestern roots and "to draw attention to the fight against breast cancer, and celebrate survivorship."

Gary Dourdan as Warrick Brown
Born: December 11, 1966
Birthplace: Philadelphia, PA
Marital Status: Single
Credits: Please check out the IMDB Database

Six-year-old Gary Dourdan worshipped his older brother Darryl, a DJ at a local Philadelphia radio station, but Darryl died under mysterious circumstances when he fell off a hotel balcony while on a trip to Haiti. It's a mystery that remains unsolved to this day, but Darryl's influence has steered Gary's life. He became a DJ in Philadelphia and now, along with his acting career, produces jazz musicians for a European label.

His break in acting came when he was in Paris and ran into actress and director Debbie Allen on the Champs D'Elysees. He sent her his audition tapes, and kept doing it, until one day he got a callback and landed a role as what he affectionately called a "jive-talking knucklehead" on A Different Strokes.

His career has spanned film and television, with roles such as Malcoln X in the telemovie Muhammad Ali: King of the World, movies Imposter, Alien Resurrection, Playing God, Scarred City, New Jersey Turnpikes and The Weekend. On television, he has appeared in Cold Feet, Soul Food, Beggars and Choosers, and New York Undercover.

When CSI first launched, Gary, like his co-stars, thought it was good but never expected it to last or became the hit series it is now. He's enjoying working on the series, as we ll as the latitude from the producers so that he can work on both CSI and make movies at the same time.

Gary resides in Venice Beach, California.

George Eads as Nick Stokes
Born: March 1, 1967
Birthplace: Fort Worth, TX
Marital Status: Single
Credits: Please check out the IMDB Database

Full name: George Coleman Eads III.

George Eads grew up in Belton, Texas, born to Arthur Eads, a district attorney, and Vivan, a junior high school principal. George was a typical Texas boy, and became a football player in high school. He acted in school plays, but when he went onto college, he earned his business degree from Texas Tech University. But the business world wasn't for him, and he attended the Texas KD Studio Acting Conservatory.

Like many aspiring actors, George moved to Los Angeles, where he took on a variety of odd jobs to pay the rent, all the time auditioning for roles. He finally landed the role of Travis Peterson on the Aaron Spelling soap, Savannah, but the thrill was short-lived. His character was killed off in the pilot. On the plus side, his appearance tested well with audiences so he returned, in a time-honored soap fashion, as the dead man's twin brother.

A small role on the NBC power drama ER soon beckoned. It started small, but soon George's character became the guy you wanted to hate: he became a block between George Clooney's and Julianna Margulies characters.

Film credits include telemovies such as Monte Walsh with Tom Selleck, Just a Walk in the Park, Crowned and Dangerous, and Evel Knievel. On TV, he was in the CBS series Grapevine and Strange Luck.

In time, CSI was being cast, and Nick got the role after two auditions for the role. Little did he know that he would soon be a familiar face to millions of viewers around the globe. And co-star Jorja Fox labels him the biggest practical joker on the set.

George lives in Hollywood in a two storey home with his Labrador Maverick, who even comes to work with him.

Jorja Fox as Sara Sidle
Born: July 7, 1968
Birthplace: New York, NY
Marital Status: Single
Credits: Please check out the IMDB Database

Jorja Fox was born in New York City to French Canadian parents and raised in the small coastal town of Melborne Beach, Florida, but moved back to NYC after she won a modeling contest in Florida. Soon she began a modeling career, which took her various places, including Milan. At eighteen, she decided to concentrate on acting, studying with veteran actor William Hickey at New York's Lee Strasberg Institute. She made her movie debut in the 1989 independent flick, The Kill-Off.

In the 1990s, Jorja obtained roles such as the ABC Afterschool special Summer Stories: The Mall and Dead Drunk: The Kevin Tunell Story, as well as HBO's Lifestories: Families in Crisis. In 1993 she did a primetime series, Law & Order, then landed a regular role on ABC's Missing Persons, but it was her portrayal of Dr. Maggie Doyle on ER that propelled her on to bigger roles. She had a recurring role on NBC's West Wing as Secret Service agent Gina Tuscano, but then CSI came along.

Her film roles have included The Jerky Boys, Dead Funny, Alchemy, the critically acclaimed Memento with Guy Pearce, as well as television miniseries The House of Frankenstein. In addition to those mediums, Jorja is co-founder of the experimental theater group Honeypot Productions, and writes and stars in plays for the Los Angeles-based group. So far, she has written four of the group's five plays. The fourth play, Lovely Stanley, is a comedic romp about the women's bowling circuit.

Jorja lives in Los Angeles, and enjoys travelling, playing guitar, and singing. She has a boxer named Ali, and two cats named Rumplestiltskin and Sid Poitier (they came with those names).

Also credited as Jorjan Fox.

Paul Guilfoyle as Captain Jim Brass
Born: April 28, 1949
Birthplace: Boston, MA
Marital Status: Married, wife and daughter
Credits: Please check out the IMDB Database and the Internet Theatre Database

Paul Guilfoyle is a busy veteran actor whose roles have ranged from theater to film to television.

His theatrical credits include Broadway productions of The Basic Training of Pavlo Hummel, Search and Destroy, Richard III, and Glengarry Glen Ross.

His feature film credits include Random Hearts, Anywhere but Here, The Negotiator, Amistad, Air Force One, L.A. Confidential, Ransom, Extreme Measures, Striptease, Quiz Show, Mrs. Doubtfire, Wall Street and Primary Colors.

On the small screen, Paul has appeared in the mob show Wiseguy, Kate & Allie, Law & Order, and Miami Vice. Made-for-television movies include Notorious, September, Curiosity Kills, Unnatural Pursuits, and Amelia Earhart.

Eric Szmanda as Greg Sanders
Born: July 24, 1975
Birthplace: Milwaukee, Wisconsin
Marital Status: Single
Credits: Please check out the IMDB Database

Eric was born in Milwaukee and raised in the small suburban town of Mukwonago. Eric was active in theater throughout his school years; in fact, by the time he was 17, he had performed in nearly 20 plays. After graduating high school, he attended Carroll College in Wisconsin, participating in a variety of theater arts productions. Soon thereafter, he moved to California where he attended and graduated from the American Academy of Dramatic Arts in Pasadena, California. At one point was cast as Lysander in a touring production of A Midsummer Night's Dream, which took him as far as the Ukraine and Russia. He returned to Los Angeles to take on the role of Nick, the suicidal self-abusive teenager in the Odyssey Theatre's world premiere of Black Box. Television was around the corner, and he won the role of Jacob Resch, a 'skateboarding computer hacker,' in the USA Network series The Net. When the series was cancelled, he temporarily put aside his music business to concentrate more on acting, winning the lead role of Johnny Dodge, a "fearless, thrill seeking private investigator with a taste for fast cars and faster women" in the UPN pilot Dodge City. The show wasn't picked up for the fall schedule, so he took on a variety of guest roles in show such as Zoe, Three Sister, Freakylinks, The Division and more. Movie roles came in, such as the independent film True Vinyl, and a supporting role in 100 Girls. He's kept active in stage work, appearing in AADA-West Theater productions such as Moonchildren, Living Quarters, G.R. Point; the Long Beach Operas La Indian Queen where portrayed Acasco, the Stages Theatre Centre premiere of The Bullfight in the lead role.

Eric was also music consultant on Irwin Winkler's film Life as a House. Recently, he and co-founder co-founder/collaborator Jonathan Pavesi have been working on developing projects including a DVD series, a monthly club/digital film festival, and a TV show based on their own experiences as a young kid in the record industry.

Robert David Hall as Dr. Al Robbins
Born: November 9, 1947
Birthplace: East Orange, NJ
Marital Status: Married
Credits: Please check out the IMDB Database.

Robert David Hall is an accomplished film and television actor who has appeared in movies such as The Negotiator and Starship Troopers, as well the Emmy-award winning TNT mini-series Andersonville. His television appearances include West Wing, Judging Amy, Family Law and course CSI as coroner Dr. Robbins. He says that he got the role because "they chose me because they thought I looked like a coroner."

Viewers may notice that Hall occasionally uses a cane in his role as the coroner. It's not a prop, but something he uses in his daily life. On July 10, 1978, at the age of 31, he was driving along in his Volkswagen when an 18-wheel truck, driven by a drunk driver, crossed the median and struck his vehicle head on. He was trapped in the burning car but fortunately rescued by a passing motorist and a firefighter. The burns, over 65% of his body, were so severe that his legs were amputated above the knee. His first stint in the burn ICU was three months long, and and he spent 3 months in the burn ICU unit, as well as many more months recovering. He now uses prothestics to walk. His role in the 1991 film Class Action closely parallels his life.

Hall is active in advocating changes for the disabled in the entertainment industry, and serves on professional, government and charitable boards, such as Media Access Office (to create opportunities for people with disabilities), and Other Voice Playwright's Lab (for disabled actors in theater).

Besides acting, Hall is a disc jockey for an alternative music station, announces for national commercials, and plays guitar and sings with live band.

Reiko Aylesworth as ?
Born: December 9, 1972
Birthplace: Chicago, IL
Marital Status: Single?
Credits: Please check out the IMDB Database.

Reiko (pronounced Ray-co) is ¼ Japanese, was born in Chicago, Illinois and when she was 13, her family moved to Seattle, Washington. It was there that Aylesworth began acting. After graduating from the University of Washington, she moved to New York City, where she performed in off-Broadway plays and landed a role in the daytime soap One Life to Live. Her career then picked up, with guest appearances in various television shows, as well as regular roles in shows such as American Embassy, All Souls and most recently, Fox's 24.

Aylesworth's film credits include Committed, Fathers and Sons, No Deposit No Return, Man on the Moon, Shooting Vegetarians, Random Hearts, You've Got Mail, Childhood's End.

TV shows (as a regular) include: 24, Amercian Embassy, All Souls, Sherman's March, and the soap One Life to Live (1993-94) Guest spots on TV include Pure 24, The Dead Zone, Ed, Law & Order: Special Victims Unit, The West Wing, Now and Again, Law & Order, Lifestories: Families in Crisis, and in made-for-TV films A Will of Their Own and Someone Had to be Benny. Her theatrical credits include Eric Bogosian's Humpty Dumpty, off-Broadway shows Kissing Christine/Missing Marisa, and Robbers.

David Berman as David Phillips
Born: ?
Birthplace: ?
Marital Status: ?
Credits: Please check out the IMDB Database.

No information as yet.

Archie Kao as Lab Technician Archie Johnson
Born: December 14, 1973?
Birthplace: Washington, DC
Marital Status: Single
Credits: Please check out the IMDB Database.

Archie David Kao grew up in the suburbs of Alexandria, Virginia, but now calls Los Angeles his home. As a child, he was in acting but thought about becoming a lawyer. Fortunately, acting won out and Archie is an accomplished actor who is known to many TV viewers as Kai Chen, the Blue Power Ranger, on the popular series. He has done a number of television and film roles, and enjoys traveling in his off time.

Glenn Morshower as Sheriff Brian Mobley
Born: Dallas, TX
Birthplace: April 24, 1959
Marital Status: Married
Credits: Please check out the IMDB Database.

Although little is known of this versatile character actor, Glenn can be seen in a wide range of shows and movies. His work ranges from Dallas to JAG to Enterprise on television, and from movies such as The Philadelphia Experiment to the acclaimed Blackhawk Down. Check the IMBD link above his extensive credits.

Glenn lives in California with his wife.

Skip O'Brien as Sgt. O'Riley
Born: August 20
Birthplace: Jersey City, NJ (although calls Union Beach, NJ, his home)
Marital Status: ?
Credits: Please check out the IMDB Database

Skip is an accomplished actor in both screen and theatre for over 20 years. He has appeared in a variety of plays, such as Equus (Brookdale Players), MacBeth Did It (Barn Theater), Ginger Bread Lady (Monmouth Players), and Murder in Strange Places (L.A. Press Club). His film work includes Blow, The Muse, Black Sheep, A Very Brady Sequel, Prizzi's Honor, and Perfect Prey.

His work as a character actor on television is extensive: Burning Zone, Love and War, High Incident, General Hospital, The Wonder Years, L.A. Law, The Torkelsons, Over My Dead Body, Mancusco FBI, Jake and the Fatman, Highway to Heaven, Max Headroom, and Malcolm in the Middle.

Skip has over 80 TV commercials to his credit, including award winning spots for American Airlines, as well as True Value, in which he both appeared and did the narration. He was also be spotted as the diner owner in the popular Pepsi ad with the little girl.

Skip graduated from Keyport High School in Keyport, NJ in 1968, and graduated with a degree in Theater in 1979 from the Brookdale College.

He currently resides in California.

Biographical information courtesy of Larry Hennessey.

Geoffrey Rivas as Detective Sam Vega
Born: ?
Birthplace: California
Marital Status: ?
Credits: Please check out the IMDB Database.

Geoffrey is a native Californian who graduated from UCLA in 1985 with a Master of Fine Arts degree with a concentration on acting. This producer/actor has a recurring role as Det. Vega on CSI, but is heavily involved in the theater. He received the 1999 Ovation nomination for his role as Martin on Sam Shepard's Fool for Love at the Madrid Theater in Canoga Park. He is a member of The Latino Theatre Co., created by Jose Luis Valuenza at LATC, and works with the Virginia Avenue Project (of which he is a board member), an organization that uses performing arts to encourage children growing up under difficult circumstances to achieve their full potential.

Theatrical credits include: I Don't Have To Show You No Stinking Badges and Piano (LATC). Man of the Flesh (South Coast Rep). Once Removed (New Mexico Rep). Dementia (Latino Theater Company).

Film credits include: La Bamba, Born in East L.A., Pow Wow Highway, Bound By Honor, Above Suspicion, Notes From Underground, Eye for an Eye, The Right To Remain Silent, Under the Tuscan Sun and Foto Novelas for PBS, for which he won an ALMA award in 1998.

He has made guest appearances on television. Some of these shows include movies of the week such as Little Assassin, Drug Wars - The Kiki Camarena Story, Overkill, Blind Side, Ambush at Waco, Trial by Fire, and The Lake. TV appearances: Jake And The Fat Man, L.A. Law, E.R., Relativity, Chicago Hope, Brooklyn South, Alright Already, Early Edition, Pensacola, Air America and Promised Land.

Jeffrey L. Sams as Detective Cyrus Lockwood
Born: June 18
Birthplace: Cincinnati, Ohio
Marital Status: Married
Credits: Please check out the IMDB Database.

The youngest of seven children, Jeffrey was born in Cincinnati, Ohio. His mother, noticing his creative tendencies, made him attend the School of Creative and Performing Arts where he excelled in acting. He received several scholarships and attended Webster University in St. Louis. Upon graduation, Jeffrey went to Chicago where he received critical acclaim in A Midsummer Night's Dream. Broadway was next, where he was in plays such as The Wiz, Big River, Five Guys Named Moe, Little Shop of Horrors, and The Taming of the Shrew, to name a few.

In 1993, he attracted the film industry's attention as Rich, a subway token clerk who leaves everything he knows to become a rap artist in Fly by Night (winner of the Trophy Award at the Sundance Film Festival in 1995). He appeared as Whitney Houston's would-be suitor Lionel in Waiting to Exhale, then as Viveca A. Fox's husband in Soul Food.

His television appearances include Green Dolphin Bend (Fox, 1994), Automatic (HBO, 1995), Run For the Dream: The Gail Deevers Story (Showtime, 1996) and Hope (TNT, 1997). He was also in a three-episode arc of Law & Order, and a regular on shows such as Sleepwalkers, Courthouse, Medicine Ball, Loving and Cupid. He has appeared in or had recurring roles in Law & Order (three-episode arc), Living Single, Boston Common, Thea, and The Commish.

Jeffrey lives in Los Angeles with his wife, Lisa, and their Himalayan cat, Frank. He actively supports Equity Fighting AIDS and several other AIDS causes.

Jeffrey's character appeared in season 3 of CSI.

Marc Vann as Conrad Ecklie
Born: ?
Birthplace: ?
Marital Status: ?
Credits: Please check out the IMDB Database.

Marc worked for 15 years in Chicago theater for 15 years before he moved to Los Angeles to tackle film and television. His theatrical work includes With and Without, Night and Day, The Seagull, Flyovers (Victory Gardens), The Crypogram, The Libertine As I Lay Dying (Steppenwolf), All The Rage, All's Well that Ends Well Three Sisters, Light Up The Sky, The Notebooks of Leonardo DiVinci, , Journey to the West, Black Snow (Goodman), and nearly two dozen plays with the Center Theatre Ensemble.

He has appeared in films such as Ghost World, Stranger Inside, Payback, Hoodlum, and The Forsaken. On television, some of his numerous guest appearances include CSI, The Guardian, NYPD Blue, Malcolm in the Middle, For the People, Early Edition, JAG and Monk.

Marc has a tie to CSI... as a Chicago actor, he appeared in the play Flyovers with William Petersen.

Marc's character appeared in seasons 1-2 of CSI.