In Season 1, Jason Gideon leads the BAU team along with fellow profilers Aaron Hotchner, Elle Greenway, Derek Morgan, and genius-geek Spencer Reid. Their task is to establish psychological profiles of criminals and think as they do in order to solve heinous crimes. Some of the more memorable cases during Season 1 include the "Footpath Killer," the "Tommy Killer," an LDSK (Long-Distance Serial Killer), and a "Son of Sam" copycat killer.
After a fourth woman goes missing in Seattle in a period of four months, the BAU is brought in to track down the abductor before he kidnaps again. Meanwhile, SSA Aaron Hotchner is asked to evaluate SSA Jason Gideon secretly to determine if he is really ready to work full-time again after returning from a six-month leave of absence.
The team of investigators tries to capture a serial arsonist who has been terrorizing a college campus. Most of the evidence from the fires had been burned beyond recognition, so Gideon and the BAU must rely on psychological analysis to identify the firestarter.
Gideon and the BAU track down a copycat bomber who has been terrorizing a quiet community. They determine the bomber is mimicking Gideon's nemesis, Adrian Bale, the man responsible for murdering Gideon's team in Boston several years earlier.
The BAU travels to San Diego to stop a rapist and murderer who commits his crimes in the middle of the day. The suspect appears to blend into the neighborhood so well the local authorities have been unable to capture him.
The BAU investigates the kidnapping of a U.S. District Attorney's daughter and determines the kidnapper isn't seeking money - he is after her twin sister. The case becomes complicated because the kidnapper is always one step ahead of them.
The BAU is asked to identify a killer who is shooting at victims in broad daylight, and the team works with local law enforcement officers to recreate one of the shootings.
The BAU profiles a serial killer who takes families hostage and lives with them as a father figure during what is supposed to be their family vacations.
When an undercover cop involved in a mob investigation goes missing, the BAU believes a serial killer rather than the mob has something to do with his disappearance. The probe leads to several unsolved missing persons cases.
Elle, along with many others, is held hostage on a train in Texas by a paranoid schizophrenic who is convinced that the U.S. government is monitoring him. Hotchner and Gideon are forced to play into the man's fantasy to save the people he has taken hostage.
The BAU is called to investigate the murder of two small-town high school students who may have been victims of a cult killing. Based on the crime scene evidence, the team begins to believe it is possible that someone other than a cult member may be responsible.
While Gideon is sidelined on crutches at FBI headquarters, Hotchner and the BAU go to Tennessee in an attempt to get inside the mind of a psychotic killer whose disorganized and erratic fantasies lead him to murder.
When a young girl is abducted in broad daylight from a playground in a seemingly safe neighborhood, the BAU initially believes her father is responsible. When he is able to provide an alibi, the team is forced to look for clues near where the girl lives to determine who is really responsible.
The team travels to New Jersey where several people have been poisoned, one fatally, with LSD 10 times more potent than the street version.
After interviewing a married couple sitting on death row for serial murder, Gideon suspects the woman is actually innocent. But since she's set to be executed in two days, it's a race against time to prove it.
A serial killer reappears after 20 years of silence and contacts the BAU through Gideon's retired mentor, who had made his life's work tracking the killer, with the promise he will kill another victim in the next five days.
When college students in New Mexico are found tortured and murdered in an unoccupied house, the BAU suspects a group of killers with a knowledge of Native American rituals is responsible.
The BAU travels to New York City to investigate a series of murders that appear to have been committed by a vigilante who is exacting revenge on other criminals who have been released by the justice system.
Reid finds himself in danger when he falls for a starlet whose stalker has turned into a killer.
The BAU travels to Mexico to aid in the capture of a serial killer who has targeted elderly women.
The BAU works to capture a serial killer who has evaded capture by altering his appearance.
The BAU works with the CIA to identify a mole within that organization whose leaks are putting operatives at risk.
While on their separate vacations, each member of the BAU receives a clue from a psychopathic killer who challenges them to save his next victim.