CSI is an innovative, new type of crime drama because the characters use cutting-edge forensic tools to examine the evidence to solve the case. Rather than a 'whodunnit' cop show (investigating witnesses/suspects), CSI explores the 'howdunnit'. CSI has been the number one scripted series in the Neilsen ratings for four years running. In 2007 nearly 84 million people watched CSI, making it the most watched show in the world. CSI is now in it's 9th amazing season.