From Wikipedia:
CSI: Crime Scene Investigation (also referred to as CSI and CSI: Las Vegas) is an American police procedural drama television series that premiered on CBS October 6, 2000. The series, starring William Petersen, Marg Helgenberger, Laurence Fishburne, Ted Danson, and Elisabeth Shue, is the first in the CSI franchise. The series concluded on September 27, 2015, after 15 seasons, with a feature-length finale titled Immortality.
Mixing deduction and character-driven drama, CSI: Crime Scene Investigation follows a team of Crime Scene Investigators, employed by the Las Vegas Police Department, as they use physical evidence to solve murders. The team is originally led by Gil Grissom (William Petersen), a socially-awkward forensic entomologist and career criminalist who is promoted to CSI Supervisor following the death of a trainee investigator. Grissom's second-in-command, Catherine Willows (Marg Helgenberger), is a single mother with a cop's instinct. Born and raised in Vegas, Catherine was a stripper before being recruited into law enforcement and training as a blood spatter specialist. Following Grissom's departure during the ninth season of the series, Catherine is promoted to Supervisor. After overseeing the training of new investigator Raymond Langston (Laurence Fishburne), Willows is replaced by D.B. Russell (Ted Danson), and recruited to the FBI shortly thereafter. The series' twelfth season sees Russell, a veteran of the Seattle Crime Lab, and his former partner Julie Finlay (Elisabeth Shue), reunite to tackle Las Vegas' growing crime rate. Russell, a family man and keen forensic botanist, is on the case 24/7, scouring the scene, collecting the evidence, and finding the missing pieces that will solve the mystery. Finlay, like Catherine, is a blood-spatter expert with an extensive knowledge of criminal psychology.