The team is called in to investigate the apparent overdose death of a heroin addict but soon find subtle traces of foul play.
When a young woman seemingly dissapears from her university campus and no trace can be found, the CSI team run into road block after road block as they have many suspects but no clear cut case.
Grissom investigates an apparent suicide of a construction worker but evidence of electrocution points to murder. Catherine and Nick investigate the death of a teenager who died during a therapy session and the shrink may be directly responsible.
The team investigates the murder of a high school student who is a top jock, class clown and apparently the school bully, which gives them a compelling motive. Also, Sara and Nick look into a rotted corpse found in a bag which turns out to be a former soldier.
A scuba diver is found dead in a tree, nowhere near a body of water, and a girl's apartment is splattered with blood but seems to be missing after she supposedly went to visit her parents and never arrived.
When a man is caught red-handed burying bodies, Grissom deems the evidence too obvious to take at face value and investigates further. Meanwhile, Catherine looks into the case of a woman who apparently expired as a result of hot-tubbing.
While Grissom and Nick look into the death of a book restorer found dead in a temperature controlled room, Catherine and Sara investigate a collision between an SUV and a train.
A naked corpse found in a park with whip marks and evidence that she was tied up lead the team on an investigation into the Las Vegas bondage scene.
While half the team investigates a casino heist in which innocent bystanders are killed, the other half investigates a murder in the desert. Eventually, both sides realize the two incidents are connected.
Captain Brass' daughter is implicated in the murder of a con artist, the investigation leads to a counterfeiting ring.
After a real estate developer is found poisoned in an elevator, the team finds the crime scene tampered with and the body's organs donated, making the investigation nearly impossible to complete.
While the team investigates a possible murder when two bodies are discovered dumped inside pipes, Nick and Catherine lead an investigation of an apparent hunting accident.
As the team looks for serial killer Paul Millander, Grissom realizes he may well be a target.
Catherine is dragged into the middle of a kidnapping investigation of a man's mistress as she is forced to accompany the ransom drop or risk the victim's murder.
A photographer's dead body is dumped and evidence leads them into a child abuse case where he may have taken nude photos of a young woman.
Half the team investigates the death of a soccer player whose throat gets slashed in the middle of a dog-pile while Warrick and Nick investigate the death of a saxaphone player who seems to have died of a drug overdose.
When four Buddist monks are murdered, Grissom must figure out why while Catherine investigates the closed case of her best friend's murder when the convicted killer claims his innocence before he dies.
A deadly bus crash reveals evidence of foul play when one of the passengers, recently paroled, is not among the victims.
When a woman is killed by a stalker in locked-down house, the murder strikes a particular chord with Nick, who becomes a target himself.
Grrissom and Catherine look into the stabbing death of an old woman who lived in squalor with her many cats while Nick and Sara's investigation into a car bombing reveal more than they expected.
A body of a male corpse is found buried in a park, covered in lye which leads to a hit-and-run with a twist and a woman's body is found drowned in the middle of a desert and her boyfriend becomes suspect.
When a former police chief is found slain and his wife and daughter are missing, Grissom investigates in Vegas while Catherine and Warrick follow the trail of the daughter to Miami where they get the help of their local CSI team.
When the team investigates the murder and facial mutilation of a model found dead under a freeway, suspicion turns to her homeless and mentally unstable sister.