Greg, for his final proficiency, has to determine how the Sherlock Holmes of a Sherlock Holmes club was killed. Nick and Warrick try to determine how the driver of jeep was killed when the car ran off the road. They have to do this under budget while Catherine is watched by Ecklie.

A serial killer strikes again, and the CSI team tries new technology using evidence from a prior killing. They find a fingerprint belonging to Jesse Acheson, who becomes the prime suspect. A boy confesses to the killing of his brother, but evidence suggests that he may not have committed the crime.

The team must investigate the death of a police officer who died during a shootout leaving hundreds of bullets on the crime scene. The case becomes complicated when it turns out that Sofia Curtis and Jim Brass were with the victims during the shootout. When it turns out the officer died from friendly fire, it is up to the team to find out who fired the fatal shot. Meanwhile, Sofia is wondering whether she fired the fatal shot or not. She decides to hide the fact that the officer stepped into her line of fire, afraid it will ruin her career.

The CSIs sift through the overwhelming evidence from a shootout with drug dealers in order to determine who is responsible for the death of a police officer killed during the incident.

The CSIs become the focus of a reality TV series, which follows them while they investigate a serial rapist, who recently gained access to a woman's apartment by posing as a fireman. Also, Warrick's work on the late-shift is causing problems with his marriage to Tina.

At Keppler's request Catherine uses a different approach to catch the killer, and in doing so she deceives the rest of the CSI team. The team soon discovers that something is amiss in Catherine’s investigation.

Grissom returns from his sabbatical; Keppler is put into a compromising position when the bodies of a Trenton police officer and a hooker are found in a hotel room. The man who found them is a retired New Jersey cop and close friend to Keppler, who doesn't reveal their relationship.

The CSI team investigates two unusual cases, one involving the suspicious death of a go-cart racer who took his hobby to the highway and paid the price with his life, and a murder at a hip new restaurant where patrons dine in the dark

While Langston testifies in the trial of a respected Congressman, new evidence sends the CSIs back to the lab to reopen the investigation.

The CSIs dig to find the truth about how a recent shootout at a gun store might connect to a young woman who may have committed suicide.

Catherine and Detective Vartann are thrown together in a hotel room for 24 hours as they stake out a duo making drugs in the room next door. Meanwhile, Nick and Langston work a case that involves a fetish which has become big business in Vegas.

While investigating the murder of a convicted ex-cop, the CSIs stumble upon a list in his prison cell with names of several individuals he believed might have been his wife's true killer.

A string of deaths, including a gamer found dead on his couch and a newly divorced man at the bottom of a pool, instigate a bet among the CSIs as to whether they've "hit for the cycle" - a homicide, a suicide, an accidental and a natural death all in one night

Three new murders related to three unsolved (or incorrectly solved) crimes from the past come back to haunt the CSIs.

When the CSI team is called in to investigate a man who is shot at point-blank range in a local casino, they shut down the entire building to find their killer.

A body is discovered during torrential rain in Vegas; Sanders is accused of framing a man for murder seven years ago.