CSI Actors You May Not Know Passed Away

"CSI: Crime Scene Investigation" and its spin-off series comprise one of the most popular television franchises of the 21^st century; a 2006 profile by the Independent noted that the first three series in the franchise — "Crime Scene Investigation" (which ran from 2000 to 2015), "CSI: Miami" (2002-2012) and "CSI: NY" (2004-2013) — were syndicated to an audience of more than two billion in 200 countries. Since then CBS, which oversees all things "CSI," has added two more iterations: "CSI: Cyber," which ran from 2014 to 2016, and "CSI: Vegas," which brought the franchise full circle and featured a number of the original series' stars, including William Petersen (as forensic scientist Gil Grissom) and Marg Helgenberger (investigator Catherine Willows), in 2021.

At the heart of each "CSI" episode is a crime that requires scientific research in order to determine the cause and culprit. That arrangement requires a lot of actors to handle the guilty party, various witnesses, secondary investigators, and (of course) the victim of the week. As a result, a small army of performers has passed through the "CSI" franchise, many of whom appeared in one episode and then went on to other projects. 

Of course, the franchise has now been around for more than  twenty years, so some faces you may remember from years past may no longer be with us. Below is a (spoiler-ish) breakdown of "CSI" actors you might not know passed away.

Among the many lawmen who regularly accompanied the CSI team to crime scenes, Detective (and later Sergeant) Ray O'Riley was immediately identifiable by his burly frame and close-cropped buzz cut. Though rarely afforded more than a supporting role in his 24 appearances on "CSI" Seasons 1 and 4, O'Riley was a tenacious investigator — he handled key questioning of suspects and witnesses in Season 1's "Boom" and Season 2's "Felonious Monk" — before his final appearance in Season 4's "Homebodies." O'Riley was mentioned as one of the fatalities in a shooting rampage at the Las Vegas Police Department in Season 14's "The Fallen."

Actor Skip O'Brien, who played O'Riley in all 24 appearances, played a host of similar roles throughout his quarter-century career in television and on film. The Jersey City, NJ native and former US Marine was a go-to for cops and blue-collar types for decades in films like "Prizzi's Honor," "Liar Liar," and "Blow," as well as series like "Ally McBeal" and "The Wonder Years." He advanced to heftier supporting roles following the exposure afforded by "CSI": O'Brien was a protective father of an injured son on a Season 10 episode of "ER," and a county sheriff investigating Sean Bean's murder spree in the 2007 remake of "The Hitcher." He made his final screen appearance in an unsold Fox pilot, "The Madness of Jane," in 2008; after returning to New Jersey in 2010, O'Brien died at the age of 60 in 2011.

Character actor Scott Wilson lent folksy charm and understated drama to nine episodes of "CSI" as former casino boss Sam Braun, who also happened to be Catherine Willows' father. His familial connection to Catherine was revealed in Season 3's "Assume Nothing" by a blood test; the emotional turmoil of the news was further complicated by his gift of a sizable check for her daughter's education. The push-and-pull relationship between Catherine and Sam peaked in the Season 7 two-parter, where his link to a crooked investment deal resulted in the kidnapping of Catherine's daughter. While Lindsey was rescued, Sam was shot and killed by his former partner.

A veteran of film and television for over a half-century, Wilson initially rose to fame by playing complicated criminals: a murder suspect in the Oscar-winning "In the Heat of the Night" and real-life killer Richard Hickock in Truman Capote's "In Cold Blood," both from 1967. He remained active in character parts — some kindly, others menacing — for the next three decades, earning a Golden Globe nomination for William Peter Blatty's cult thriller "The Ninth Configuration" and appearing in films like "The Right Stuff" (as aviator Scott Crossfield), "Dead Man Walking," and Bong Joon-hoo's "The Host." Wilson received excellent notices as the sympathetic veterinarian Hershel Greene on "The Walking Dead," and enjoyed recurring roles on "Bosch" and "The OA." He died from leukemia at the age of 76 at his home in Los Angeles, California on October 6, 2018.

Actress Lisa Sheridan logged appearances on three different series in the "CSI" franchise. The first of these came with a minor role in "Bloodlines," which capped Season 4 of "CSI: Crime Scene Investigation"; Sheridan then enjoyed a four-episode arc on Season 6 of "CSI: Miami" as Kathleen Newberry, a woman pulled into a complicated web of kidnapping and murder that involved Horatio Caine's troubled son. Sheridan's last "CSI" guest shot came in Season 7 of "CSI: NY" as the mother of a missing young girl.

A frequent guest star on episodics like "The Mentalist," "Scandal," and "The Fosters," Sheridan was also a series regular on two highly-publicized but short-lived sci-fi-related dramas: Fox's "FreakyLinks" and ABC's "Invasion." Her feature film work included the 2000 indie "Beat" with Ron Livingston, to whom she was briefly engaged. The 45-year-old Sheridan was found dead in her home in New Orleans on February 25, 2019; an autopsy obtained by RadarOnline later determined that the cause of death was complications from chronic alcoholism.

If you or anyone you know needs help with addiction issues, help is available. Visit the Substance Abuse and Mental Health Services Administration website or contact SAMHSA's National Helpline at 1-800-662-HELP (4357).

A recurring character on "CSI: NY" between Seasons 3 and 4, Inspector Stanton Gerrard complicated matters for Mac Taylor and the CSI team in six episodes by launching investigations into how they handled their cases. A former captain promoted to Deputy Inspector, Gerrard developed a reputation as a hard-nosed cop that rivaled Mac for toughness. However, the pair put aside their differences in Season 4's "Admissions," where Mac showed a degree of care for Gerrard after he killed a suspect who assaulted his daughter.

Veteran character actor Carmen Argenziano played Gerrard on "CSI: NY" and also guested on "CSI: Crime Scene Investigation" as a mobster linked to a prosecutor's murder in Season 6's "Rashomama." The Pennsylvania native began his career on TV in the late '60s and balanced guest roles on episodic series with supporting turns in features throughout the 1970s; the latter included everything from low-budget exploitation ("Caged Heat") to one of Michael Corleone's gunmen in "The Godfather, Part II." By the '80s, he became a familiar face to small screen audiences via shows like "Lou Grant" and "The Rockford Files" and films like "Sudden Impact" and "Into the Night."

Argenziano remained active in both mediums well into the 2000s, amassing credits in films like "Angels & Demons" and "Gone in 60 Seconds" while also enjoying a recurring role on "Stargate SG-1" as Jacob Carter, host of the Tok'ra Selmak. As Deadline noted, he earned a unique notoriety as the helpful husband in a 2013 UnitedHealthcare AARP TV spot that aired more than 10,000 times. Argenziano died of lung cancer at the age of 75 on February 10, 2019.

In four episodes of the first season of "CSI: Crime Scene Investigation," forensic anthropologist Terri Miller offered both professional expertise to the team and romantic intrigue to Gil Grissom. Miller aided the team in identifying various skeletal remains, which clearly piqued Grissom's intellectual and emotional interest. However, their sole date in "To Halve and to Hold" was interrupted by a case, and Miller quashed any hope of a second chance. She was later revealed in Season 3 to have married a teacher.

Actress Pamela Gidley, who played Terri Miller, was a former model who turned to acting in the mid-1980s. Roles in indie features like "Permanent Record" with Keanu Reeves led to her most notable appearance as Teresa Banks, whose murder helped fuel the action in David Lynch's "Twin Peaks" universe. Her feature film work drifted into independent and direct-to-video titles in the years that followed, though she remained active on television through recurring guest roles on "The Pretender" and briefly, series regular work on ABC's "Angel Street" and Fox's "Strange Luck" and "Skin." Gidley's final role came in 2014's "Twin Peaks: The Missing Pieces," which incorporated archival footage from "Fire Walk with Me"; the 52-year-old died of unspecified causes in her home in Seabrook, New Hampshire on April 16, 2018.

Emmy nominee John Heard appeared in four episodes between Seasons 1 and 3 "CSI: Miami" as Kenwall "Duke" Duquesne, father to Emily Procter's investigator Calleigh Dusquene. Like many of Heard's best-known roles — toy executive Paul Davenport in "Big," Detective Vin Makazian on "The Sopranos," and Governor Frank Tancredi on "Prison Break" — Duke was a flawed character whose struggles with alcoholism required the intervention of the CSI team on occasion. Most notable among these was Season 3's "Under the Influence," where Calleigh must find evidence to prove her father's innocence after he's charged with a fatal hit-and-run. Heard also appeared in a Season 14 episode of "CSI: Crime Scene Investigation" as a corrupt county supervisor linked to the murder of an underage sex worker.

Major roles in theater productions during the 1970s led to Heard's screen career, which for a time in the early '80s seemed to indicate that he was a leading man with promise. However, nuanced turns in films like "Chilly Scenes of Winter" and an acclaimed starring role alongside Jeff Bridges in "Cutter's Way" failed to pull in audiences; Heard instead settled into character roles in films like Martin Scorsese's "After Hours" and "The Trip to Bountiful." Appearances in two blockbusters — "Big" and "Home Alone," which cast him as Macauley Culkin's dad — raised his profile in the 1990s and led to turns in major features like "The Pelican Brief" and "In the Line of Fire" and his Emmy-nominated role on "The Sopranos."

Heard remained exceptionally busy in the 2000s through numerous indie feature roles and guest turns on "Battlestar Galactica," "Entourage," "Modern Family," and "Elementary." While reportedly recovering from minor back surgery, the 71-year-old Heard died of cardiac arrest in a hotel in Palo Alto, California on July 21, 2017.

If you or anyone you know needs help with addiction issues, help is available. Visit the Substance Abuse and Mental Health Services Administration website or contact SAMHSA's National Helpline at 1-800-662-HELP (4357).

Rugged leading man Brad Johnson briefly sparred with and then dated Catherine Willows over the course of three episodes in Seasons 1 and 2 of "CSI: Crime Scene Investigation." Johnson's district engineer Paul Newsome met not-so-cute with Catherine in "$35K O.B.O.," which involved a building collapse that claimed the lives of three elderly women. After clearing Newsome's name, the pair appeared to date in "Justice is Served" before Johnson's third final "CSI" turn in Season 2's "Scuba Doobie-Doo." He assisted Catherine in the investigation of a dead scuba diver found in a tree, but their romance went unaddressed.

According to the Hollywood Reporter, Johnson was a former professional rider on the rodeo circuit who came to acting through a casting director looking for authentic cowboys for a commercial. This led to a three-year stint as the Marlboro Man in print and television spots for the tobacco company and roles on television. His big break came in Steven Spielberg's 1989 fantasy "Always," where he romanced Holly Hunter, but he seemed more comfortable in TV and feature Westerns like the miniseries "Ned Blessing: The Story of My Life and Times" and "Crossfire Trail" with Tom Selleck. Johnson also appeared in the 2000 faith film "Left Behind: The Movie" and its two sequels.

Johnson, who lived in Texas and sold ranch real estate there, died of complications from COVID-19 on February 18, 2022 (via Legacy.com). He was 62.

Actress Kelly Preston appeared in three episodes of the second and final season of "CSI: Cyber" as a love interest for Ted Danson's D.B. Russell, who had joined the team after the series finale of "CSI: Crime Scene Investigation." The pair met after Russell accidentally responded to a text from an unknown person, who turned out to be Preston's Greer Latimore, a private investigator. The pair's relationship blossomed into romance, and the series finale, "Legacy," found them together and relocated to Paris.

Preston made her screen debut in the notorious 1980 Charles Bronson cult classic "10 to Midnight" and quickly worked her way up to free-spirited ingénue roles in films like "Mischief" and "SpaceCamp." In the 1990s, she proved capable at both comedy ("Twins") and drama ("Citizen Ruth") and gave a memorable turn as Tom Cruise's steely ex-girlfriend in "Jerry Maguire." Preston moved into television in the 2000s, enjoying a recurring role on "Medium" as a competitive coworker at Jake Weber's job, while also making occasional returns to features like "Death Sentence" and "The Cat in the Hat."

Preston, who was married to actor John Travolta, was diagnosed with breast cancer in 2018. She underwent treatment but died from the disease at her home in Clearwater, Florida on July 12, 2020 at the age of 57. Her final film appearance came via the indie feature "Off the Rails," released posthumously in 2021.

Cody Longo appeared twice in "CSI: NY" as Tyler Josephson, the son of Sela Ward's Jo Danville, in Seasons 7 and 8. He also appeared in a Season 11 episode on the flagship "CSI" series as the boyfriend of a teenager who committed suicide after being bullied by classmates. Longo, who also performed as Cody Anthony, worked his way up from guest roles on series like "Medium" and films like "Piranha 3D" to a recurring turn on "Days of Our Lives" and a starring role as a rocker who hires a high schooler to write his songs on the Nick at Nite series, "Hollywood Heights," in 2012.

Longo also pursued a parallel career as a musician, first as a member of the band Forever the Day, and later as a solo performer. He sang the theme song for "Hollywood Heights," released a handful of singles between 2012 and 2013, and later contributed songs to "Wildflower" and "Rich Boy Rich Girl," two independent features in which he also starred. But as his career progressed, his personal life also seemed to unravel.

The New York Times quoted a representative for Longo who said that he had struggled with alcoholism for several years, and Variety noted that he had been arrested for domestic assault in 2020 and pleaded guilty to misdemeanor assault the following year after being charged with sexual assault involving a minor (via ClarksvilleNow.com) The 34-year-old was found dead, possibly from accidental alcohol poisoning, in his home in Austin, Texas on February 8, 2023.

If you or anyone you know has been a victim of sexual assault, help is available. Visit the Rape, Abuse & Incest National Network website or contact RAINN's National Helpline at 1-800-656-HOPE (4673).