William Petersen, who played played forensic entomologist Gil Grissom on CSI: Crime Scene Investigation before leaving the hit series in 2009 will appear in an upcoming episode of the crime drama, will return for a guest spot on the show this spring. Petersen has already filmed a cameo that will air at date to-be-announced later [...] Continue reading William Petersen Gil Grissom “CSI” Return Later This Season