Watch CSI: Crime Scene Investigation Online - Full Episodes

CSI: Crime Scene Investigation is a procedural drama that airs on CBS. Each episode opens with the discovery of a dead body, and the rest of the episode is devoted to the subsequent murder investigation. There is usually a subplot involving a secondary case. The original protagonist of the series was William Petersen's introverted Gil Grissom. Petersen left the show in 2010, and Laurence Fishbourne stepped in for two dreary seasons. CSI finally regained its trademark energy and wit when Ted Danson joined the cast last season.

Like its predecessor Law & Order, CSI's success lies in its format. Characters come and go, but the scientific approach to solving mysteries remains captivating. The scientists on CSI use real and fictional technology to draw answers out of the tiniest bits of evidence. Unbiased science is used to bolster the investigators' idealistic morals; the show has a moral sensibility that it maintains by only rarely depicting the court proceedings in which the killers are convicted. Viewers see the evidence and learn who the killers are. There is no reasonable doubt. Most episodes end right after the killers are revealed.

CSI is set in Las Vegas, and many episodes touch on the city's seedy history. The fascinating mafia lore lends some gravity to the scientific proceedings. Special effects, animations and flashbacks of the crimes keep the series from being morbid. Grounding the casual conversations about murder in Las Vegas legends gives CSI an air of mystique that other procedurals lack.

The show originally focused on Grissom and Marg Helgenberger's sassy Catherine Willows as the lead investigators, but the supporting characters gradually grew to warrant more screen time. Even the lab technicians occasionally have episodes all to themselves. Every few years there is a long-running arc featuring a serial killer that eludes the team for an entire season.

The small, disconnected vignettes featured on CSI add up to reveal something deep and dark about humanity at large. Evidence will always reveal how a crime was committed, but the investigators sometimes struggle to determine a killer's motivation. People who are on the right side of the law need to understand what it feels like to want to kill someone. CSI explores this contradiction and draws compelling drama from it. The show plays a joke on audience members, who are now affected by this contradiction as well. CSI remains at the head of the procedural pack.