On September 2, 1944, as the Second World War was in progress in Europe and the Pacific, some strange happenings were reported in the small town of Mattoon, Illinois. The front page of the town’s newspaper described a mysterious attack by an “Anesthetic Prowler” the previous evening. A young housewife named Aline Kearney had been laying in bed reading the newspaper when she noticed a strong, sweet odor seeping into the room. The smell made her and her three-year-old daughter feel ill, but when Aline tried to get out of bed, she found that she couldn’t move her legs.

Aline’s sister was staying at the house, and upon learning of the strange odor and its ill effects, she dashed to a neighbor’s house to have them contact the police. When the police investigated they found nothing out of the ordinary, but when Aline’s husband arrived at home at 12:30am from his job as a cab-driver, he discovered a prowler outside the bedroom window. He gave chase, yet the unknown lurker escaped. When the police were summoned back, they again found nothing. Real or imaginary, the dark figure would soon come to be known as the Mad Gasser of Mattoon, and this ambiguous individual would be blamed for dozens of such attacks in the following weeks.

Such is how the story was told in the Daily Journal-Gazette the following day, under the headline “‘Anesthetic Prowler’ on Loose.” The subheading ominously declared, “Mrs. Kearney and Daughter First Victims.” In using the term “first,” it seems that either the Gazette reporters had an uncanny predictive ability, or they had a flair for the dramatic. In the days following the news report, three other citizens came forward claiming that they had been the victims of “gassings” before the event at the Kearney house. People spoke of lightheadedness, paralysis, upset stomach, and vomiting, accompanied by a sickly-sweet odor.

A few days later on September 5, Mrs. Carl Cordes reported finding a small wet cloth on her porch, and when she picked it up she was overcome by an odor. “It was a feeling of paralysis,” she reported, “My husband had to help me into the house and soon my lips were swollen and the roof of my mouth and my throat burned. I began to spit blood and my husband called a physician. It was more than two hours before I began to feel normal again.”

Other newspapers quickly picked up the story, and soon the entire country was reading about Mattoon’s rumored mad gasser. For months, U.S. newspapers had been warning Americans that the Nazis might employ poison gas in attacks against civilians, so this sort of story sold a lot of newspapers to jittery citizens.

Reports of “gassings” continued, and increased daily. On September 8, the Gazette published an editorial criticizing police for not taking Aline Kearney’s report seriously. Shortly thereafter, ten Illinois state police officers were assigned to the case, as well as two agents from the FBI.

Before long, police began to receive reports of several attacks each night. Many victims reported a tall figure dressed in black fleeing from their property immediately after the attacks, as well as blue vapors and buzzing sounds. The Gazette continued its coverage as people throughout the country read of the events unfolding in Mattoon. Soon, large groups of armed citizens were roaming the town at night, following any police cars that were speeding off to investigate another attack. Police officers were ordered to start arresting the chasers, and tensions mounted.

On September 13th, eight days and three dozen victims later, the reports of attacks abruptly halted. Investigators were at a complete loss for an explanation. Careful searches found no chemical evidence of harmful gasses, and all of the victims were completely free of any lingering symptoms.

The only suspect ever investigated in the attacks was a man named Farley Llewellyn. He was a student of chemistry, and he was bitter because he had been ostracized by the community as a suspected homosexual. He seemed a compelling suspect because he had the means and the motive, and most of the alleged attacks occurred near his home. But even after he was placed under constant surveillance, the reports of the attacks had continued.

To this day, it is unclear who was responsible for the attacks, if anyone. Some have postulated that pollutants from nearby factories and industrial plants may have been the cause, but each report was so localized as to cast that possibility into doubt. The official investigation ultimately dismissed the Mad Gasser as an artifact of mass hysteria fed by the newspapers, which is certainly not outside the realm of possibility. It wouldn’t be the first nor the last time that human imagination and embellishment conjured a threat from nothing.