Dr. Raymond "Ray" Langston comes into contact with the CSI team in the course of a murder investigation and joins the Las Vegas Crime Lab as a level 1 CSI. Langston is a medical doctor who used to work in a hospital. A co-worker murdered 27 patients, and all the evidence showed up before him, but he never put the evidence together. Ray had trouble for the most part of his first season. His first day on the job was most troubling for him, he was held hostage in the aftermath of a shootout in a neighborhood, one of Ray's former students was murdered, and Ray once had to shoot and kill a murderer in self-defense. Ray was promoted to CSI level 2 in the season ten opener and it was explained that he spent his time off taking every class and seminar he could to really become the CSI that Gil Grissom saw in him. Ray also revealed that he was raised in Korea and that his father was a veteran of the Korean War, who frequently got into brawls. Also, Ray traveled to Miami and New York, involving a case that crosses over into all the three CSI shows for the first time. In the season ten cliffhanger, the Dick-and-Jane Killer stabbed Ray, but it is revealed in the season eleven premiere that Ray survives. He moves away to help console his ex-wife after she had been kidnapped, raped, and tortured by the Dick-and-Jane Killer.