Laboratory Technician Sam Belmontes (, seasons 1–2, 10): Chemical Analysis lab tech.
Cristian de la Fuente
Laboratory Technician Tyler Jenson (, seasons 1–3): Audio/visual and multimedia lab technician who was later replaced by Dan Cooper.
Brian Poth
Laboratory Technician Cynthia Wells (, seasons 2–5, 8–10): Questioned Documents lab tech.
Brooke Bloom
Laboratory Technician Carrie Delgado (, season 2): Blood evidence technician. She was a fan of Quincy, M.E. as a child, influencing her to become a criminalist. She only appeared in season 2, as two years later, DeHuff died from pneumonia.
Nicole DeHuff
Laboratory Technician Joseph Kayle (, seasons 2–4): A lab tech who worked in fingerprints.
Leslie Odom Jr.
Laboratory Technician Maxine Valera (, seasons 2–8): DNA analyst. She was temporarily suspended from her duties in season 3 for technical errors and was then reinstated by season 4.[1] She has an unfortunate habit of taking shortcuts with evidence, which caused her suspension and also brought her under suspicion when the lab was investigated by the FBI (episode 4.25, "One of Our Own"). She goes on a date with Natalia Boa Vista's ex-husband, Nick Townsend, and thinks she is his killer after he turns up murdered, though this assumption is proved to be untrue. Jake Berkley (who investigated the case) kept insisting she and Natalia had killed him, despite the fact that Townsend was brutally beaten to death. She and Natalia were cleared, however, when it is revealed that Nick Townsend's death is related to the case of Lauren Sloan and her husband Jeff Murdock. Jeff killed Nick to get back his wife's earring (episode 5.12, "Internal Affairs"). Her final appearance was in "Delko for the Defense".
Boti Bliss
Laboratory Technician Aaron Peters (Armando Valdes-Kennedy, seasons 3–4): A trace evidence lab tech. He did not like Eric Delko in his lab while working his sister's case being in his lab. He filed a report, but later regretted it when the lab falls under federal investigation. Presumably, as a result of the intense pressure the FBI was giving the Crime Lab, Peters most likely quit his job or at his own request was transferred to work elsewhere.
Laboratory Technician Nicole Talcott (, season 3): A lab tech from the night shift of the Miami Dade Crime Lab. She temporarily filled in for Valera after the latter was suspended for putting a rape victim's DNA and profile into the system.
Kimiko Gelman
Laboratory Technician Daniel "Dan" Cooper (, seasons 4–6): He believes a great deal of information can be discerned by what music a person has on his or her MP3 playlist (episode 5.17, "A Grizzly Murder"). He had a good relationship with the Crime Lab personnel and also the CSIs until the season 6 episode "Bang, Bang, Your Debt", when he is discovered to have stolen and used a credit card that belonged to the late Tim Speedle—to the outrage of Delko and Calleigh, who told him to turn himself in or she would issue a warrant for his arrest. Presumably, this instance of identity theft was the final nail in the coffin for Cooper and ended his career at the lab, prompting him to resign from the lab for good, in disgrace. As a result, he holds a personal grudge against Calleigh for this, despite the fact that she does not press charges, and steals the flashcard out of her camera at a crime scene to put the pictures on a website he has created to "take her down a notch." He also changes her cell number and posts it on the site, and she is kidnapped from a "lead" (episode 6.16, "All In"). After an enraged Delko confronts him, Cooper later feels remorseful and turns in evidence that helps the team track down Calleigh, free her, and arrest her kidnappers.
Brendan Fehr
Laboratory Technician Jim Markham (, season 4), Ballistic lab tech. Markham became the head of the ballistics section when Calleigh left after John Hagan committed suicide there, but unfortunately, Markham made regular mistakes such as leaving skin cells unexamined on a bullet casing. Calleigh later grew tired of Markham screwing up and returned to the Ballistics lab, which also resulted in Markham being transferred elsewhere.
Joshua Leonard
Laboratory Technician Dave Benton (, seasons 7–10): Audio/visual tech for the Miami Dade Crime Lab, who is a rock-star type of guy. (Ramsey had previously appeared as Kip Martin in the season 1 episode, "Spring Break".)
Wes Ramsey
Laboratory Technician Michael Travers (Christopher Redman, seasons 7–10): British trace analyst. He has a background knowledge about horse racing which was helpful for a case (7.13, And They're Offed). He always seemed to be nosy about what was going on about a case, but showed he cares about the team.
Laboratory Technician Nikki Vega (, season 9): A lab technician who moved to Miami from another crime lab (it was never mentioned from where). Only appears in two episodes.
Alexandra Adi
Medical Examiner Tom Loman (, seasons 8–10): His work genuinely seems to excite him despite its macabre nature, even performing an autopsy on the fly for some medical students on a cadaver donated to science, which was eventually discovered to be a victim of a crime the CSIs were investigating. He occasionally laments at how violent people can be to each other, as a contrast to his usually upbeat demeanor, but it only strengthens his resolve to discover what killed those that entered his morgue. He often becomes frustrated or upset when anyone, including the CSIs, interrupts him whenever he runs with a theory or conducts an examination, or makes them wait until his theory is confirmed or if the evidence denies it, even going as far as to prevent them from collecting evidence off of the body until he conducts his examination in the autopsy room.