It is September 1, 1944. The United States is in the middle of the most devastating war in human history. American boys are dying on beaches in France and in jungles in the Pacific. The newspapers are full of casualty lists and bond drives and factory production numbers.
In the small industrial city of Mattoon, Illinois — population around 16,000 — the war is something that happens to other people's sons and husbands. Life here is factories, farms, tight community bonds, and the particular quiet of a Midwestern town that has sent its young men away and is waiting for them to come home.
On this particular September evening, Aline Kearney is sitting in her bedroom. Her husband is at work. The children are asleep. The night is warm and ordinary.
Then the smell hits her.
Sweet, slightly floral, with a chemical edge she can't identify. She thinks she must be imagining it. Then the paralysis starts — a strange, spreading numbness moving up from her legs. Her lips begin to swell. Her mouth goes dry. Her throat tightens. She tries to stand and cannot.
By the time her husband Bert Kearney arrives home and finds her barely able to speak, the smell has already faded. But the symptoms remain. She is taken to the hospital — where doctors, unable to identify the cause, treat her symptoms as best they can and send her home.
The next morning, the Mattoon Daily Gazette runs a story with a headline that will define the next several weeks of life in this Illinois town:
"Anesthetic Prowler on the Loose."
What followed over the next two weeks was one of the strangest, most genuinely disturbing, and most completely forgotten episodes in American domestic history. Someone — or something — was gassing the residents of Mattoon, Illinois in the middle of World War II. The police investigated. The FBI got involved. The state health department sent investigators. Every scientific resource available was deployed.
Nobody was ever caught. Nobody was ever charged. Nobody was ever conclusively identified.
The Mad Gasser of Mattoon simply stopped — and disappeared — as completely and mysteriously as he or she had begun. And today, more than 80 years later, the case remains officially unsolved.
Mattoon, Illinois in 1944: A Town Under Pressure
The Weight of Wartime
To understand why the Mad Gasser of Mattoon created the terror that it did, you need to understand the psychological state of the town he chose.
Mattoon in 1944 was a community under significant stress. The city's primary employer was the Atlas Imperial Diesel Engine Company — which had converted to war production and was running at full capacity, with workers on multiple shifts around the clock. The Burgess Battery Company and several other industrial operations added to the industrial character of the town.
The air in Mattoon in 1944 smelled, on some days, of industrial chemicals — a fact that would become enormously relevant as the mystery developed. Residents were accustomed to occasional strange smells from the factories. They were also accustomed to being told, during wartime, to be alert for unusual threats.
The wartime anxiety was real and pervasive. Air raid drills were conducted regularly. Blackout curtains were required. The newspapers were full of stories about enemy agents, saboteurs, and the dangers of chemical weapons — which both sides in World War II were known to possess.
Into this atmosphere of industrial odors, wartime anxiety, and genuine fear — someone, or something, introduced a real or imagined chemical threat. And the town of Mattoon was psychologically primed to believe the worst.
The Atlas Imperial Connection
One detail that investigators would return to repeatedly was the proximity of the Atlas Imperial plant to many of the reported gassing incidents. The factory used carbon tetrachloride and other industrial chemicals in its manufacturing processes. These chemicals, in certain concentrations, can cause exactly the symptoms reported by Mattoon residents — nausea, paralysis, difficulty breathing, and a characteristic sweet chemical smell.
This is not a trivial observation. It forms the backbone of one of the most serious explanations for the Mattoon events — and we will return to it. But it does not explain everything. Because if industrial emissions were the cause, why did the attacks follow such a specific, targeted pattern? Why did they occur at specific houses and not others? Why did they stop completely — and immediately — after a particular date?
The Atlas Imperial theory explains the symptoms. It doesn't explain the gasser.
The Attacks: A Chronicle of Terror
September 1 — The Kearney Incident
The Kearney incident was the first reported attack — and the one that set the pattern for everything that followed.Aline Kearney's symptoms were documented by a physician and reported to police. The smell she described — sweet, slightly nauseating, with a chemical quality — matched no common household substance. The paralysis in her legs, lasting several hours, was medically documented. The swelling of her lips was observed by her husband.
This was not a woman reporting vague discomfort. These were specific, measurable physical symptoms, confirmed by a doctor, with a consistent onset that matched the smell she described.
Significantly — a neighbor reported the same smell at approximately the same time that evening, without having spoken to Aline Kearney or knowing about her symptoms. Two independent witnesses. Same smell. Same time. Same street.
The Mattoon Daily Gazette ran its story the next morning. And the town of Mattoon began to watch its night with new and frightened eyes.
The Attacks Multiply
Within 48 hours of the Gazette's story, new reports began flooding in. By September 5th, eight separate gassing incidents had been reported to police. By September 8th, the number had grown to fifteen. By the time the attacks ended in mid-September, approximately 25 official incidents had been reported — involving nearly 35 victims, most of them women, many of them on the same streets and in the same neighborhoods.
The pattern of the attacks was consistent and deeply unsettling:
- Incidents occurred almost exclusively at night
- Victims reported the same sweet, nauseating chemical smell
- Physical symptoms were remarkably consistent across all victims — nausea, lip swelling, temporary paralysis of the legs, difficulty breathing
- Symptoms typically lasted between 30 minutes and several hours
- The smell always disappeared quickly — by the time police arrived, it was gone
- In several cases, witnesses nearby reported the same smell independently
The Mattoon police chief, C.E. Cole, was initially skeptical. But as the reports multiplied and the pattern became impossible to dismiss, he called in help. The Illinois State Police sent investigators. The state health department dispatched chemists. And — in the context of a nation at war — the FBI opened its own file on the Mattoon events.
Someone was gassing American civilians in the Midwest. And nobody knew who, or why, or what they were using.
"💡 Did You Know? The 1944 Mattoon attacks occurred during a period of intense American anxiety about chemical warfare. Both Allied and Axis forces possessed large stockpiles of chemical weapons during World War II, and the fear of domestic chemical attacks by enemy agents was taken seriously by US authorities. When the Mad Gasser reports reached federal level, investigators considered — and did not immediately dismiss — the possibility of enemy sabotage."
The Victims: Real People, Real Symptoms
Who Was Being Targeted?
Analysis of the reported victims revealed a pattern that investigators found both intriguing and troubling.
The overwhelming majority of gassing victims were women — specifically, women who were home alone while their husbands worked night shifts at the wartime factories. This was not a random distribution. Of the approximately 35 official victims, fewer than 10 were male.
This pattern has been interpreted in two very different ways depending on which theory of the case you favor.
If the Mad Gasser was real — a human being deliberately targeting Mattoon residents — then the pattern suggests a calculated predator who knew which houses would be occupied by women alone at night, who understood the shift schedules at the factories, and who had chosen his victims deliberately. This interpretation is deeply disturbing, because it implies a level of local knowledge and planning that points directly to someone within the Mattoon community itself.
If the attacks were mass hysteria or misidentified industrial emissions — then the pattern suggests that women home alone at night were simply more likely to notice and report unusual smells, more likely to be in a psychological state of anxiety that amplified genuine mild symptoms, and more likely to connect their discomfort to the newspaper reports of the gasser.
Neither interpretation is comfortable. The first suggests a predator who was never caught. The second suggests that dozens of women were disbelieved and their real physical suffering dismissed as psychological weakness.
The Most Seriously Affected Victims
While many victims recovered within hours, some suffered more seriously. Mrs. Beulah Kearney — a neighbor of the original Aline Kearney — reported such severe symptoms that she required hospitalization for several days. Multiple victims reported symptoms that persisted for more than 24 hours. Several described a burning sensation in their mouths and throats that lasted for days.
The physical consistency of the symptoms across victims who had not spoken to each other, who lived in different parts of the town, and who reported their attacks on different nights — this is the evidence that most seriously undermines the pure mass hysteria explanation.
You can argue that anxiety amplifies symptoms. You cannot easily argue that dozens of unconnected women independently invented the same specific symptom profile — the lip swelling, the leg paralysis, the sweet smell — without any real physical trigger.
"Women being harmed by chemical exposure — and then disbelieved by the authorities around them — has a painful history in America. The Radium Girls of the 1920s experienced exactly this: their bodies were being destroyed by radioactive paint, the evidence was overwhelming, and the corporate and medical establishment dismissed their suffering for years before being forced to acknowledge the truth. Read their full story on Tenebora."
The Investigation: Police, Scientists, and the FBI
Chief Cole's Investigation
Police Chief C.E. Cole conducted the ground-level investigation in Mattoon with the resources available to a 1944 small-city police department — which were limited. His officers responded to every reported attack, collected victim statements, canvassed neighborhoods for witnesses, and searched the areas around attacked homes for any evidence of the attacker.
They found nothing. No footprints that couldn't be explained. No discarded containers. No suspicious vehicles. No witnesses who had seen anyone near the homes before the attacks. The gasser, if real, was extraordinarily careful — or extraordinarily lucky.
Cole set up night patrols throughout the affected neighborhoods. Officers in unmarked vehicles circled the streets where attacks had been concentrated. Residents were asked to report anything unusual immediately.
During the period of the night patrols — the attacks continued.
The State Health Department's Findings
The Illinois State Health Department sent a chemist named Dr. Thomas V. Wright to Mattoon to investigate. Wright's investigation produced findings that remain central to the debate about the Mad Gasser.Dr. Wright tested the air in and around the homes of several victims. He found traces of chlorinated hydrocarbons in several locations — specifically compounds consistent with carbon tetrachloride and similar industrial solvents used at the Atlas Imperial plant.
Wright's conclusion was cautious but significant. He stated that the chemical traces found were consistent with the symptoms reported by victims — and that industrial emissions from the nearby factories could not be ruled out as the source.
But he also noted something that the industrial emission theory cannot comfortably explain: the chemical traces were found in concentrations too low to cause the severity of symptoms reported. The amount of chemical present in the air samples wasn't enough — on its own — to produce paralysis and severe nausea in healthy adults.
This left two possibilities. Either the samples were taken too long after the attack events, when concentration had already dispersed. Or something else — something more concentrated, more specifically targeted — had been used.
The FBI File
The FBI's involvement in the Mattoon case is one of the most underreported aspects of the story. In the context of wartime America, a series of chemical attacks on a civilian population — even a small Midwestern city — was taken seriously enough to warrant federal attention.
The FBI opened a file on the Mattoon events. Agents conducted interviews. Records were reviewed. The possibility of enemy sabotage — a Japanese or German agent targeting industrial workers or their families — was considered and investigated.
The FBI file was eventually closed without conclusion. No enemy agent was identified. No foreign connection was established. But the file exists — a federal document confirming that the United States government took the Mattoon attacks seriously enough to investigate at a national level.
And they found nothing.
Professor Tainter's Controversial Conclusion
The Mass Hysteria Theory
In 1945 — just months after the Mattoon attacks ended — a professor of sociology at the University of Illinois named Donald M. Johnson published a paper in the Journal of Abnormal and Social Psychology that would define the academic conversation about the Mad Gasser for the next half-century.
Johnson's thesis was direct and dismissive: the Mattoon attacks were a case of mass hysteria driven by irresponsible newspaper reporting. The Gazette's initial story about the "anesthetic prowler" had planted a suggestion in the minds of anxiety-prone residents. Subsequent reports amplified that suggestion. And psychologically vulnerable women — already stressed by wartime separation from their husbands — had converted that suggestion into physical symptoms through the power of suggestion.
In Johnson's analysis, Aline Kearney's initial symptoms were real — but caused by industrial emissions from the nearby Atlas Imperial plant, not by any human attacker. Every subsequent case was either the same industrial emissions misidentified, or genuine psychosomatic illness produced by the anxiety of reading about the gasser in the newspaper.
Johnson's paper was widely cited and became the dominant academic explanation for the Mattoon events. For decades, if you looked up the Mad Gasser of Mattoon in any psychology or sociology textbook, you would find it presented as a textbook case of mass hysteria — interesting primarily as an example of how media can manufacture collective delusion.
Why Johnson's Theory Has Problems
However, Johnson's mass hysteria explanation has been subjected to serious academic scrutiny in recent decades — and it has not held up well.In 2003, researchers Michael Showalter and Robert Bartholomew published a detailed reanalysis of the Mattoon case in the Journal of the History of Medicine and Allied Sciences. Their findings challenged almost every aspect of Johnson's original conclusion.
Showalter and Bartholomew found that Johnson had misrepresented the geographical distribution of the attacks. Johnson had claimed that the reported incidents clustered around the location of the Gazette offices — suggesting that people who read the paper first were most likely to report symptoms. In fact, careful mapping of the incidents showed no such clustering. Victims were distributed across the town in patterns that don't match a newspaper-driven hysteria model.
They also found that Johnson had understated the medical documentation of the symptoms. The lip swelling, leg paralysis, and other specific physical symptoms reported by multiple victims were medically observed and recorded — not merely self-reported. It is extremely difficult for mass hysteria to produce consistent, medically verifiable physical symptoms across unconnected individuals.
And they pointed out the most uncomfortable fact of all: if the Mattoon attacks were mass hysteria, what caused the symptoms of the very first victim — Aline Kearney — before any newspaper story had been published, before any community suggestion had been introduced, before any "hysteria" could have spread?
Something made Aline Kearney sick on the night of September 1, 1944. Whatever it was, it was real.
The Prime Suspect: A Name the Town Never Forgot
Farley Llewellyn
While the official investigation never charged anyone, the residents of Mattoon had their own theory about who the Mad Gasser was. And that theory pointed to one specific individual — a man named Farley Llewellyn.
Llewellyn lived approximately six blocks from the Kearney home — the site of the first attack. He was a trained chemist. He had studied chemistry at the University of Illinois and had a fully equipped home laboratory. He was known by neighbors to be eccentric, socially isolated, and deeply interested in chemical experiments.
He was also known to have a troubled personal history — described by some contemporaries as unstable, with a reputation for unusual behavior that made his neighbors uncomfortable.
The circumstantial case against Llewellyn is not trivial. He had the knowledge to produce a compound capable of causing the Mattoon symptoms. He had the equipment to do so. He lived near the epicenter of the attacks. And his background and behavior fit — at least in the popular imagination — the profile of someone capable of targeting his neighbors with a chemical agent.
However. No physical evidence ever linked Llewellyn to the attacks. No witness ever placed him near any of the attack sites on the nights in question. He was never arrested, never charged, and never convicted of anything in connection with the Mattoon events. He denied any involvement until his death.
The suspicion of Llewellyn may have been justified — or it may have been the community finding a convenient target for its fear and anger. Without physical evidence, it is impossible to say which.
What is certain is that Farley Llewellyn lived in Mattoon for the rest of his life under a cloud of community suspicion that never entirely lifted — accused of a crime that was never proven, never charged, and never solved.
"💡 Did You Know? The Mad Gasser attacks stopped abruptly on September 13, 1944 — thirteen days after they began. There was no announcement. No capture. No explanation. The attacks simply ceased, as completely and suddenly as they had started. Mattoon Police Chief Cole noted the cessation but could offer no explanation for it. The abrupt ending — consistent with a deliberate decision to stop rather than a natural phenomenon running its course — is one of the strongest arguments for the reality of a human attacker."
"Mysterious events that stop as suddenly and completely as they began — with no explanation — are one of the most unsettling features of dark history. In 1518, the residents of Strasbourg were consumed by an unstoppable dancing plague for weeks — and then, one September morning, it simply ended. Nobody has ever satisfactorily explained why it stopped any more than why it started. Read the full investigation into the Dancing Plague of 1518 on Tenebora."
The Modern Reinvestigation: What Do We Know Now?
Scott Maruna's Research
The most comprehensive modern investigation into the Mad Gasser was conducted by researcher Scott Maruna, who published a book titled The Mad Gasser of Mattoon: Solving a Lingering Mystery in 2003.
Maruna spent years researching the case, accessing historical records, court documents, and local archives that had not been previously examined by researchers. His conclusions were the most specific and most evidence-based of any investigator who had looked at the case.
Maruna's primary target was Farley Llewellyn — but he approached the identification differently from the community gossip that had surrounded Llewellyn for decades. Rather than relying on suspicion and reputation, Maruna mapped the attacks geographically and temporally and found that the distribution of incidents showed a clear pattern consistent with a single individual operating from a specific location.
That location was consistent with Llewellyn's home and laboratory.
Maruna also investigated the specific chemical compounds most likely responsible for the Mattoon symptoms and found that several compounds that would have been accessible to a trained home chemist in 1944 — including carbon tetrachloride mixtures and certain chlorinated solvents — could produce the exact symptom profile reported by victims when deployed in the concentrations that a targeted attack would involve.
His conclusion: Farley Llewellyn was most likely the Mad Gasser — a deeply troubled individual with the chemistry knowledge and the personal instability to conduct targeted attacks on his neighbors, who stopped when community suspicion made continuing too risky.
The Problem with Maruna's Conclusion
Maruna's work is serious and carefully argued. But it faces the same fundamental problem as every other theory about the Mad Gasser: there is no direct physical evidence linking anyone to the attacks.
No gas canister. No laboratory residue connecting to victim symptoms. No witness placing the attacker at any scene. No confession. Llewellyn denied involvement and was never given the opportunity to defend himself in any formal legal proceeding — because he was never charged.
Maruna's case is circumstantial. It is the best circumstantial case available. But in the absence of direct evidence, it remains a theory — not a conclusion.
And so the Mad Gasser of Mattoon remains, officially, unidentified.
Why Nobody Talks About This
The Mad Gasser of Mattoon should be one of the most famous unsolved mysteries in American history. Consider what it involves:
- A series of deliberate chemical attacks on American civilians
- During wartime, in a major industrial city
- Investigated by local police, state authorities, and the FBI
- With medically documented victims
- And a prime suspect who was never charged
By any reasonable measure, this is an extraordinary case. A human predator — if the attacks were real — targeted dozens of women in their homes over two weeks, used a sophisticated chemical agent, evaded every law enforcement effort deployed against them, and then simply stopped.
And almost nobody knows about it.
The most likely reason is Professor Johnson's 1945 paper. By labeling the Mattoon events as mass hysteria within a year of their occurrence — before any serious counter-investigation could be conducted — Johnson effectively closed the case in the public mind before it had been properly opened. The academic consensus calcified around his explanation, and the case was filed away as a curiosity of wartime psychology rather than an unsolved criminal investigation.
The victims of the Mattoon attacks — the women who suffered real, documented physical symptoms in their own homes — were told, in effect, that what happened to them was their own imagination. Their suffering was reframed as weakness.
That reframing may have been wrong. And its wrongness has never been properly acknowledged.
"The pattern of ordinary communities being harmed by mysterious substances — and then receiving no adequate explanation from the authorities — has repeated itself across history. In 1994, the residents of a small Washington State town called Oakville experienced something remarkably similar — gelatinous blobs raining from the sky six times in three weeks, making people seriously ill and killing animals, while the official investigation quietly produced nothing. Read the full story of the Oakville Blobs on Tenebora."
Mattoon Today: A Town That Moved On
The Mad Gasser attacks ended on September 13, 1944. Life in Mattoon returned to its wartime normal — rationing, factory shifts, anxious waiting for news from overseas. The gasser became a story that old-timers told and younger residents had vaguely heard of.
The town of Mattoon still exists. Today it has a population of around 17,000 people — slightly larger than in 1944. It has a Walmart, a few restaurants, a hospital, and the quiet character of a Midwestern industrial town that has weathered a century of economic change.
There is no official memorial to the Mad Gasser events. No historical marker on the street where Aline Kearney first smelled the gas. No museum exhibit. No annual remembrance.
The attacks of September 1944 are mentioned in local history, acknowledged as having happened, and otherwise treated as a curiosity — a strange episode in a strange year, best left to researchers and curious outsiders.
Farley Llewellyn died in Mattoon without ever being charged with anything. He took whatever he knew — or didn't know — to his grave.
The FBI file on the Mattoon events is now accessible through the Freedom of Information Act. It is not particularly illuminating — a collection of interview records and field reports that ultimately add up to "we investigated and found nothing definitive." But it exists, a permanent federal record confirming that in September 1944, someone — or something — was attacking the residents of a small Illinois city in a way that the entire investigative apparatus of the United States government could not explain or stop.
"💡 Did You Know? The Mad Gasser of Mattoon case has been cited in academic literature as one of the most contested examples of the mass hysteria diagnosis in 20th-century American history. Several modern researchers have argued that the mass hysteria label has been systematically misapplied to cases involving real physical events — and that Mattoon is one of the most significant examples of this misapplication. The debate between the hysteria explanation and the real attacker explanation remains genuinely open in the academic literature."
The Two Verdicts: What Do You Believe?
After more than 80 years, the Mattoon case demands a choice. The evidence points in two directions — and only one of them can be true.
If the Mad Gasser was real — a human being, almost certainly Farley Llewellyn or someone with similar chemistry knowledge and local access — then the Mattoon attacks represent one of the most sophisticated and successful criminal acts in American history. A deliberate chemical attacker who targeted dozens of victims over two weeks, evaded every law enforcement effort, and was never identified or charged. The victims were right all along. And the dismissal of their testimony as mass hysteria was a serious institutional failure that denied them justice.
If the attacks were mass hysteria and industrial emissions — then the Mattoon case is an important lesson in how media, anxiety, and community suggestion can transform real but mild physical discomfort into a full-scale collective crisis. The victims experienced something genuine, but misattributed it to a human attacker who never existed. The lesson is about the extraordinary power of belief and suggestion on the human body.
Here is what the evidence actually supports: the first attack on Aline Kearney was real. Something chemical caused her documented symptoms before any newspaper story had been published and before any community hysteria could have developed. What happened after that — whether subsequent attacks were the same attacker, industrial emissions, or genuine psychosomatic illness amplified by the newspaper reporting — remains genuinely uncertain.
The Mad Gasser of Mattoon is not a story about whether mass hysteria is real. It is a story about what happens when a community is harmed, the authorities can't find the cause, and the easiest available explanation is chosen over the most complete and honest investigation.
And it is a story that has been almost completely forgotten — which, depending on your view of how it ended, may be exactly what someone wanted.
"The full academic debate between the mass hysteria explanation and the real attacker theory is documented in detail in the Journal of the History of Medicine and Allied Sciences — specifically in the 2003 paper by Showalter and Bartholomew that challenged Donald Johnson's original 1945 conclusions and reopened the case for modern scrutiny."
"Wikipedia's detailed article on the Mad Gasser of Mattoon provides the most comprehensive publicly available timeline of the attacks, the investigation findings, and the academic debate between the mass hysteria and real attacker theories."
Conclusion
In September 1944, something attacked the residents of Mattoon, Illinois. It came at night. It smelled of sweetness and chemicals. It left its victims paralyzed and nauseated, their lips swollen, their throats burning. It targeted women alone in their homes. It evaded the police, the state health department, and the FBI. And then, after thirteen days and approximately twenty-five reported incidents, it simply stopped.
The Mad Gasser of Mattoon is one of the most completely forgotten significant mysteries in American history — dismissed too quickly, investigated too shallowly, and buried too conveniently under an academic label that may have been applied more to close a troubling case than to genuinely explain it.
The victims of Mattoon deserved better. Aline Kearney deserved better. The dozens of women who reported real, documented physical symptoms in their own homes — and were told that their suffering was a product of their own anxious imaginations — deserved better.
Whether the Mad Gasser was a real human being who was never caught, a tragic confluence of industrial emissions and wartime anxiety, or something the evidence hasn't yet fully explained — the residents of Mattoon were harmed. Their government investigated and found nothing. And the story was filed away as a curiosity and forgotten.
Eighty years later, the file is still technically open. The Gasser is still officially unidentified. And Mattoon, Illinois has moved on — carrying the story in its local memory like a bruise that never quite healed, in a place most of the world has never thought to look.
What do you believe happened in Mattoon in September 1944? Was there a real Gasser — still unidentified, still uncaught — or did an entire American town convince itself it was under attack?
Read more dark history stories on Tenebora — and subscribe to never miss an untold mystery.