Because Warrick naively assumed simple uniformed cop Hal Watson would have arranged a search warrant, the crucial weapon in the rape and murder trial on a neighbor against Michael Fife is dismissed as evidence in court. A.D.A. Jeffrey Sinclair can only get a 24 hours delay to present new evidence to build the case again. Nick brilliantly smooths emotional waywardness from Sarah and Warrick. New clues expected to reconstruct the case against Fife actually indicate he's probably innocent. An alternative culprit must be found, starting from Fife's car where the bloody knife was planted.

Dr. Robbins concludes that a woman covered with red blotches has not died of Ebola. In the autopsy, he learns that the woman is Julie Stern, who was recovering in the hotel from a cosmetic procedure. He also tells to Catherine that she had urine in her stomach and signs of heavy metal poisoning. Catherine and Nick interview her doctor, Tony Malaga, who owns an expensive clinic. When Dr. Robbins finds the same symptoms in the autopsy of Renita Loakes, they return to the clinic with a warrant to get their medical information. Meanwhile, Grissom, Sara, Greg and Capt. Brass investigate the death of Elliot Beckman, whose house was fumigated and his body was found inside. The exterminators tell them that the house was supposed to be empty when they released the gas.

When a group of fraternity members find a spot covered by maggots, Grissom investigates the scene and believes a student is providing the flesh to the maggots. Based on the uniform size of the bones and woods, Nick and Grissom believe a mulching machine was used to discard the body, and soon they find evidence in the machine. Based on a fingernail found in a garbage bag, Catherine concludes that the Blue Painter Killer is back. Now the entire team is working on the case.

When the flight attendant Martha Krell is found dead and raped in her hotel room, Grissom, Greg, Sara and Capt. Brass investigate the case. They note that there is no luggage in the room that was cleaned and sanitized without any evidence. Ecklie tells Sara that he had a similar case five years ago, with the flight attendant Sue Stein. Sara notes that the present technology is able to retrieve the fingerprint from the previous case. Meanwhile, Catherine, Nick, Warrick and Det. Chris Cavaliere investigate the case of the death of the twelve-year-old Ty Hawkins, who has been beaten to death on his bed while sleeping. His fourteen-year-old brother Matt becomes the prime suspect to Det. Cavaliere and when Matt confesses the murder of his brother, Nick questions the way Det. Cavaliere conducted the interrogation. The CSI team proceeds the investigation and finds two other suspects: Ty's father Martin and the homeless Walter. Who might be the murderer?

After a tough day at the work, Catherine invites Warrick and Nick to drink in a bar. She goes alone and meets Adam Novak, a stranger that fives his phone number in a matchbook. He offers to go to her car with her, they kiss each other and Adam turns brutal when she does not want to have sex with him. She hits her head on the door of the car and goes home. While sleeping, Catherine gets a call from Grissom and heads to the crime scene, where Alice Granger is found dead with a shot in her head. When Det. Vartann find her car nearby the bar where Catherine was, she goes with him to investigate. When she finds a matchbook in the belongings of Alice with a phone number, she heads home to find Adam's matchbook, but it has been thrown in the garbage. Their further investigation indicates that her ex-boyfriend, Jeff Simon, might be the killer, but he had a strong alibi. Catherine tries to tell to Grissom about her possible involvement in the case, but he does not give much attention to her. But when a second victim is found with the same M.O., they realize that the killer might be the same.

Catherine investigates the murder of a young mother who claimed God got her pregnant, while Grissom witnesses a very shady trial.

The CSI team is called to help when Karen Mathews reports her son, Jesse, missing from a playground where he was playing on the swings. Witnesses report seeing a man with a blue baseball cap near the swings. Clues in the park bathroom include blood and the boy's underpants. The boy is eventually found in a store, accompanied by a woman with a man fitting the earlier description. But the couple with the boy claim that he is their son Adam, while Karen insists he is her missing son Jesse.

A woman is coming home staggering when her neighbor Christina Hollis stumbles into her crying, bleeding and nervous, since she has been raped. Grissom and Catherine investigate the case and are followed by a camera and a television crew of a reality show since the sheriff has authorized them believing that it would be good for the image of the department. They collect evidences from the apartment. Sofia interviews Christina in the hospital but she has no recollections of her assault. Their first suspect is the maintenance guy but his duct tape is different from the one used in Christina. Archie examines the elevator camera and sees a young man with flowers getting off at her floor. Later he is identified as Dwight Reynolds, who used to date Christina. Soon they believe the person of interest is a fireman. When the team crosses Christina's case with other recent cases, they succeed to find the suspect.

The murder of a co-ed leads to the investigation of a brother and sister who were involved in another murder case from Sara's past, and the case drives Sara over the edge.

A mobster that Warrick had a run-in with is found dead, and Warrick is found at the scene with the murder weapon. However, he insists that he has no recollection of the crime.

A woman's unlikely suicide is tied to a bank robbery and a hypnotist, the team investigates the murder of a guidance counselor who was also a degenerate gambler, and Sara helps out in an euthanasia case.

CSI needs the help of an 8-year-old, HIV-positive boy to figure out who shot and killed his uncle and his mother during a street party in Koreatown.

When a new murder leads to a connection with an infamous serial killer, Grissom secretly joins the class of well-known criminal pathologist Dr. Raymond Langston to gain access to the killer and get a crack in the case.

Grissom gets Dr. Langston's help to find the man who is carrying on the serial killer's work before the next victim is killed. The case will prove to be Grissom's last with the crime lab.

Dr. Langston has a challenging first day learning the ropes both in the field and in the crime lab, and the team has a difficult time deciding who will get Grissom's old office.

Nick and Riley investigate the case of a badly injured skydiver, while Dr. Langston investigates the death of a religious leader out in the desert.

A young Hollywood actress is killed in what appears to be a simple drunk driving collision, but the team soon suspects that there is more to the case than meets the eye, and a shootout in the crime lab may confirm their suspicions.

Two murders occur in a neighborhood being taken over by undesirable residents, and the prime suspect has a connection to a serial killer case from CSI's past.

A mild-mannered operations support employee kills one of his co-workers. But while CSI is busy trying to figure out the killer's identity, the motive for his crime is revealed.

Catherine and Nick try to find out how a member of the band Rascal Flatts was nearly electrocuted during a concert, while Ray runs into roadblocks while investigating the death of a retired CIA chief.

The team discovers that a man who shot and killed a married couple is actually a victim of "Dr. Jekyll," and Dr. Langston could be the doctor's next target.

A comic who was one-half of a legendary Vegas duo from the 1970s is found dead on the eve of their reunion show, while the body of a fugitive who bombed an abortion clinic is dumped in Las Vegas with over 100 bullet holes in him.

The CSI team investigates a well-orchestrated bombing at the funeral of Officer Franklin Clark.

A well-known Las Vegas philanthropist is brutally slashed in her bed, and the team soon discovers that it is dealing with a killer who knows the secrets of some of the city's most prominent citizens.

Nick accidentally stumbles upon a badly decomposing dead body in the home of a mother with a severe hoarding disorder, but that is only the first of a number of grisly surprises the team finds in the house.

The CSIs set out to track down a pedophile suspected of murdering an FBI agent's wife and kidnapping his children.

While the team discovers body parts of a man and a woman in a barn, a ransom video involving one of Nate Haskell's brides arrives at the crime lab. They soon discover that the two cases are actually connected.

Dr. Langston sets out on a vigilante mission after Nate Haskell goes to Los Angeles and kidnaps his ex-wife and kills her husband.

Dr. Langston kills Nate Haskell, but was it murder or self-defense. Meanwhile, a closer look at the crime scene reveals details about Haskell's twisted past and his descent into a serial killer.

Catherine goes into hiding with D.B. after Mark Gabriel's hitmen try to kill her, but they soon come to the realization that Gabriel himself may not be calling the shots.

Three dysfunctional siblings fight over ownership of their stolen house, which contains a lot of secrets--and dead bodies.

CSI investigates a massacre at a local diner, and the team suspects that one of the victims' stalkers is the shooter.

CSI handles a case involving a rising tennis star who is killed after a big tour victory.

The evidence suggests that Sara is guilty of stabbing a man to death in a hotel room, but she insists that somebody is framing her.

The team uncovers a complex plot to rob a high-stakes Texas Hold-em game, but one of the co-conspirators may have been forced to participate against his will after his son was kidnapped.

A homeless man is found dead in an alley after suspiciously winning big at a casino, and CSI soon finds connections between the victim, two casino employees, and a local pawn shop.

The team deals with a third grisly homicide case that happens in same seedy hotel room in a couple of months.

The CSIs investigate the cyber-related murder of a prominent casino owner's wife and receive help from the FBI's Cyber Crime Division. Patricia Arquette guest stars.

The discovery of a dead body rekindles a 25-year-old mystery involving a robbery and a dead boy, and an amateur forensic investigator helps crack the case. Meanwhile, Brass's daughter is in the hospital after an overdose.

A woman in rehab at a posh Las Vegas facility is killed, and everybody at the facility is under suspicion.

Sara reopens a 10-year-old family murder/suicide case when the lone surviving daughter claims to have a new memory about that fateful evening that proves that the father didn't do it.