The fourth-season opener follows the aftermath of the bombing in New York City. Two team members are injured and the rest of the team hunt for terrorists who may be planning a bigger attack. Kate: Sienna Guillory. Sam: Michael Steger. Det. Brustin: Jack McGee. Lisa Bartleby: Moe Daniels.
The team investigates recent murders that are connected to a serial killer who was executed. Chloe Kelcher: Lauren Bowles. Shara Carlino: Blake Lindsley. Sela Dobson: Pat Destro.
Prentiss and Reid are held captive at a cult compound when they go undercover to investigate potential child abuse. Luke Perry guest stars as the cult's leader.
The team searches for a serial killer who stages his murders to look like car accidents. William Mapother and Wil Wheaton guest star.
The team hunts a serial killer targeting people who live near the railway. Jordan Todd: Meta Golding. Kevin Liman: James Black.
The case of an abducted child in Las Vegas prompts Reid to have unusual dreams that help him unlock some secrets from his childhood.
Reid conducts a solo investigation of a boy's murder that happened years earlier, believing the case has a link to his own childhood.
A serial killer (Jason Alexander) turns himself in, and the team must profile him in order to find unaccounted victims who are still alive, but may not be for long. Kaylee Robinson: Ali Landry.
Prentiss and Todd go undercover to find a serial killer who uses his fine-tuned pickup skills to ensnare women.
The team searches for a serial killer who is targeting cops in Phoenix. The case is very personal for former police officer Morgan. Cdr. Marks: Joe Regalbuto.
The team heads to Southern California to search for a serial killer nicknamed the Road Warrior, who is targeting luxury-car owners on the freeway. Faith Ford and Mitch Pileggi guest star.
A young woman disappears from her affluent Atlanta neighborhood, and the team believes someone in the community is responsible and may have had an accomplice. William Harris: Michael Boatman. Andrea Harris: Dana Davis.
A family is suspected of working together to abduct young women.
The team searches for a killer who embalms his victims in order to spend more time with them. Mrs. Gless: Cybill Shepherd. Det. Fullwood: Michael Biehn.
The team pursues a copycat murderer who is duplicating the methods of infamous serial killers.
The team searches for a prostitute who is luring and murdering business executives.
A string of deaths with religious undercurrents is investigated, and Prentiss has a personal tie to the case.
One of New England's deadliest serial killers may be murdering again after a 10-year hiatus, leading Hotchner to revisit his first case with the BAU. George Foyet: C. Thomas Howell.
A small town is terrorized by a serial arsonist targeting community meeting places.
The team travels to South Padre Island, Texas, where a serial killer is targeting students on spring break. Adam: Jackson Rathbone. Det. Evans: Roma Maffia.
A serial killer preying on children is in custody, but the case takes a twist when it's discovered that one of the murders may have been committed by someone else.
A serial killer sends the team a videotape recounting one of his murders--and also asking for help to stop killing. Vincent: Alex O'Loughlin.
The team travels to Bend, Ore., to search for a serial killer who murders victims with his car.
A killer releases a deadly virus into the open air, and one of the agents risks his life to stop the threat. Lee Whitworth: Dan Lauria.
Part 1 of 2. The team hunts for a serial killer in Detroit who targets those on the fringe of society.
Conclusion. In the fourth-season finale, the team searches for the killer in Canada, and an agent's life is threatened.