CSI: Crime Scene Investigation (season 5) CSI: Crime Scene Investigation (season 5) The fifth season of "" premiered on CBS on September 23, 2004 and ended May 19, 2005. The series stars William Petersen and Marg Helgenberger. Greg begins his journey from a lab rat to a field mouse, as the Las Vegas Crime Lab faces a personnel overhaul ("Ch-Ch-Changes"), during the fifth season of "CSI". The team's final days together are plagued with more investigations into the insane and the unusual, including the discovery of an "alien" corpse just outside the boundary of Area 51 ("Viva Las Vegas"), a body washed up in a thunderstorm
CSI: Crime Scene Investigation (season 9) CSI: Crime Scene Investigation (season 9) The ninth season of "" premiered on CBS on October 9, 2008 and ended May 14, 2009. The series stars William Petersen, Marg Helgenberger and Laurence Fishburne. As the team grieve for their fallen colleague ("For Warrick"), Grissom makes a life changing decision ("One to Go"), during the ninth season of "CSI". Also this season, Sara investigates the death of a woman attacked nine years ago ("The Happy Place"), new CSI Riley Adams joins the team ("Art Imitates Life"), and she and Nick witness a store robbery on Halloween ("Let it Bleed"), Grissom attends