Don calls upon both Charlie's expertise and the skills of new team member Special Agent Megan Reeves, a profiler, to determine who murdered a federal judge's wife.
The clock is running as Don and his FBI team dash to locate the kidnapped wife and daughter of a jewelry store owner before they are killed.
The case of a pop princess who is being stalked takes another turn as a papparazzo is found murdered after taking pictures of the star's house.
An 11 year-old boy is the only witness to the murder of his mother, a CFO of a powerful energy corporation who was about to testify against fellow executives in a stock fraud case.
Don and his team discover an elaborate code during a raid and uses Charlie's expertise to crack it after which Charlie begins to suspect that the code is part of a plan to assassinate a Columbian exile living in Los Angeles.
A counter-terrorism exercise turns deadly when one of the tests is violated by someone who unleashes a potentially lethal gas in the Los Angeles subway system.
When the number of violent home invasion-style robberies escalate in an upscale neighborhood, Charlie must find the common thread linking the crimes.
Against Don's wishes, Charlie tries to trace the origin of a disturbing photo that was discovered on the hard drive of a computer which was confiscated during a drug bust.
Don and Megan try to track down a former chemist who has been tampering with non-prescription medicine and causing people to nearly die from seizures.
The FBI is called in to investigate the murder of a researcher who specializes in Native American antiquities.
An engineering professor assists Charlie and Dr. Fleinhart in recreating a backdraft in order to assist Don in tracking down an arsonist.
Don and his team investigate a retaliation murder of an LA gang member who was actually an undercover FBI agent.
The FBI uncover a card counting scheme while investigating the murder of a young student at a card club.
The agents discover an organ-trafficking ring after a young immigrant dies while selling one of her kidneys.
One of Charlie and Larry's prize students becomes a suspect in the theft of an expensive piece of equipment from Cal Sci's DNA lab.
An anti-war bombing that kills an innocent man turns personal when the investigation dredges up surprising information on Alan Epps.
After a psychic leads the FBI to a deadly crime scene, Charlie sets out to prove that the discovery was no more than a fluke.
A female Iraqi activist is murdered on U.S soil, Don collaborates with the victims cousin Nasreen, who resides in Los Angeles. With the help of Nasreen, Don learns that the woman has a disturbing connection with Saddam Hussein.
While investigating a deadly school shooting Don and his team discover some surprising evidence that leads the team to an improbable third party to the shooting.
When an ATF agent is found dead due to an apparent suicide, Don takes a personal interest in the case when he discovers that the agent is an ex-girlfriend. Don, not completely convinced that her death was a suicide, brings his brother in to help with the investigation, things become more interesting when it is brought to his attention that he was the last person she called.
Charlies contribution to a case is jeopardized as a result of almost being shot, obviously shaken and disturbed he is hesitant to return to the office; the investigation of an arms dealer has a connection with the armed man who opened fire in the FBI office when Charlies was almost hit; Don and the team must find the crazed man motive for the shooting.
Don and his family are in danger from the Russian mob. Charlie and Alan's lives are threatened as a result of the FBI's investigaton into a computer scam that the mob is involved with. The culprits are hacking into computer bank files to access customer's indentities.
The Avian influenza virus is the culprit in the death of five young Asian girls that are found washed up on the beach, Don hurries the investigation to avoid the potential spread of the flu. The case takes a surprising turn when David and Colby discover a clue on one of the girl’s body. Charlie is forced to re-evaluate his feelings for Amita when she considers a move to Harvard University.
Don and his team must stop a suspected serial killer who drugs and kills young womenThe details surrounding a young woman's death suggests to Don and his team that she could have been murdered by a serial killer.