Criminal Minds Season 4 Episode Guide
Plot summaries for every episode of the fourth season of Criminal Minds, which aired on CBS from September 2008 to May 2009. The BAU takes on cases from a bombing in New York to a two-part hunt that crosses the Canadian border, and Hotch reopens the cold case of the Boston Reaper, a killer who makes the unit chief his personal target.
Season 4 recap
Season 4 of Criminal Minds ran on CBS from September 2008 to May 2009 with the seven regulars who ended Season 3: Aaron “Hotch” Hotchner leading the BAU, David Rossi, Derek Morgan, Spencer Reid and Emily Prentiss building the profiles, Jennifer “JJ” Jareau as liaison and Penelope Garcia as technical analyst. “Mayhem” closes the New York terror case left open in the previous finale. JJ goes into labor three weeks early in “Memoriam” and has a son, Henry; Jordan Todd (Meta Golding) covers her maternity leave until “Bloodline,” then returns to counterterrorism.
The cases include a Colorado cult standoff in “Minimal Loss,” with Luke Perry as a prophet, reportedly modeled on Jim Jones, Randy Weaver and David Koresh, who traps Prentiss and Reid inside his ranch. Jason Alexander plays a killer in “Masterpiece” who surrenders to bait Rossi, the man who caught his brother; Rossi sees the trap coming, and the five hostages survive. Mitch Pileggi is a freeway gunman in “Normal” whose family was already dead before the BAU arrived, and in “Amplification” Reid is exposed to weaponized anthrax and survives.
In “The Instincts” and “Memoriam” a recurring nightmare leads Reid to an old Las Vegas child murder and to suspect his own father, William, until he learns that the dead boy’s father killed the man Diana Reid had pointed out, and that William burned her bloody clothes to protect her. Rossi blames himself when a student whose theory he dismissed is murdered in “Zoe's Reprise.” Hotch reopens the Boston Reaper case in “Omnivore” after a dying detective confesses to a deal with the killer, who proves to be George Foyet (C. Thomas Howell), posing as the only surviving victim. Foyet escapes from a prison hospital soon after his arrest.
The finale, “To Hell…” and “…and Back,” aired on one night in May 2009. An Army veteran claims ten killings he did not commit to force a search for his missing sister and other homeless people from Detroit, and the trail leads to an Ontario pig farm where Mason Turner, a paralyzed medical school graduate reportedly based on Robert Pickton, and his brother, Lucas, have killed 89 people. The kidnapped Kelly is found alive, and both brothers end up dead. Then Hotch’s closing narration is cut short at his apartment, where Foyet tells him he should have taken the deal and a gunshot sounds, leaving Hotch’s fate unknown.
Episodes
- 1
Mayhem
After a car bomb in Manhattan leaves Hotch and a fellow agent stranded in a sealed blast zone, the BAU learns the terror cell’s real target is still to come.
- 2
The Angel Maker
When a dead serial killer’s DNA turns up at a new murder, the BAU must find the devoted copycat determined to complete his work.
- 3
Minimal Loss
When a raid on a Colorado cult goes wrong, Prentiss and Reid are trapped inside with its prophet, and the BAU must get the women and children out alive.
- 4
Paradise
When three highway crashes in Nevada prove to be staged murders, the BAU hunts a killer who traps traveling couples before he can claim another pair.
- 5
Catching Out
When a killer who makes himself at home in his victims’ houses strikes across California’s farm country, the BAU follows the rail lines to find him.
- 6
The Instincts
A woman in the grip of psychosis abducts young boys in Las Vegas, while Reid’s recurring nightmares point to a child murder from his own past.
- 7
Memoriam
Reid stays in Las Vegas to learn whether his father murdered a neighborhood boy two decades ago, as JJ’s baby arrives early back home.
- 8
Masterpiece
A killer who has studied David Rossi’s books turns himself in and dares the BAU to find a kidnapped mother and four children before his deadlines run out.
- 9
52 Pickup
A former motel killer reinvents himself as a nightclub charmer, and the BAU must work out what a pickup-artist guru taught him.
- 10
Brothers in Arms
An unseen gunman is setting deadly traps for Phoenix police officers, and the BAU must look past an easy gang suspect to stop him.
- 11
Normal
A seemingly ordinary father turns Orange County’s freeways into a shooting gallery, and the BAU races to reach his family before he does.
- 12
Soul Mates
When a jailed suspect’s alleged victim turns up freshly killed, the BAU hunts the secret partner he has been writing to online.
- 13
Bloodline
A nomadic family that has stolen girls and killed their parents for generations strikes in Alabama, and the BAU follows the clues a rejected captive remembers.
- 14
Cold Comfort
A killer embalms young women alive to recreate the woman who raised him, while a psychic’s promises to a desperate mother divide the BAU.
- 15
Zoe's Reprise
When a student who warned Rossi about a Cleveland serial killer is murdered, the BAU finds a young offender copying famous killers to discover his own style.
- 16
Pleasure Is My Business
Called to Dallas, the BAU hunts a call girl who poisons wealthy clients who abandon their families, while the men’s lawyers fight to keep their names hidden.
- 17
Demonology
When a childhood friend of Prentiss dies after a trip to Spain, the BAU traces a string of deaths to an exorcist priest shielded by diplomatic immunity.
- 18
Omnivore
After a dying detective confesses he made a deal with the Boston Reaper, the killer resumes his murders and turns his attention to Hotch and the BAU.
- 19
House on Fire
When an arsonist’s fires kill dozens in a small Indiana town, the BAU traces him to a boy the town once drove out over a rumor about him and his sister.
- 20
Conflicted
When male spring breakers are raped and murdered at a Texas beach hotel, the BAU hunts a man-and-woman team, then finds both live inside one troubled worker.
- 21
A Shade of Gray
When a third boy disappears from his home in Cherry Hill, the BAU catches a child killer but finds that the latest case doesn’t fit his pattern.
- 22
The Big Wheel
When a Buffalo killer sends police a film of a murder ending in a plea for help, the BAU hunts an obsessive-compulsive man who has killed for a decade.
- 23
Roadkill
The BAU hunts a killer in Bend, Oregon, who uses his truck to run down people who drive red coupes along a deadly highway.
- 24
Amplification
When a weaponized anthrax strain kills visitors to a Maryland park, the BAU hunts the maker under a media blackout while Reid is exposed in the maker’s home lab.
- 25
To Hell…
An Iraq War veteran falsely confesses to ten murders to force the BAU to hunt the killer he believes took his sister and other homeless people from Detroit.
- 26
…and Back
On an Ontario pig farm, the BAU uncovers dozens of victims and races to find the brother of a paralyzed doctor before he kills a kidnapped girl.