No one knows why Rudy Eugene, a 31-year-old car wash employee, suddenly launched himself at Ronald Poppo, a 65-year-old homeless man he encountered on Miami's McArthur Causeway, chewing off most of his victim's face in an 18-minute assault that ended only after a police officer shot him dead. But one thing is certain: "Bath salts" did not make him do it.

We know that because toxicological tests found no trace of synthetic cathinones, the stimulants known as bath salts, in Eugene's body. But the results of those tests were not announced until a month after the attack, which happened on a Saturday afternoon in May 2012. In the meantime, news outlets around the world, based on zero evidence aside from one police officer's speculation, attributed Eugene's savage violence to a drug he had not taken, using security camera footage of the "Causeway Cannibal" (a.k.a. the "Miami Zombie") to illustrate the horrors wrought by a nonexistent "epidemic."

Reviewing that bizarre episode in a recent issue of the journal Contemporary Drug Problems, two researchers at the University of Minnesota, neuroscientist Natashia Swalve and media scholar Ruth DeFoster, draw some lessons that could help journalists avoid such drug panics in the future. That's assuming journalists want to avoid drug panics. Their track record before, during and after the Great Bath Salt Freakout of 2012 suggests otherwise.

Swalve and DeFoster searched the Nexis database for coverage of Eugene's assault by CNN, Fox News, MSNBC, NBC, ABC, CBS and NPR. They found 31 stories: 24 from CNN, three from ABC, two from NBC and one each from NPR and MSNBC. The stories typically linked bath salts to aggression, unusual strength and hallucinations, and most referred to a recent increase in use of the stimulants; eight stories used the term epidemic. The reports featured "direct appeals (often by news anchors themselves)" for legislators to do something about the bath salt menace. "In an ostensibly impartial, fact-based medium," Swalve and DeFoster note, "it is relatively uncommon for journalists to appeal directly to legislators."

Those appeals seem to have been successful. The Drug Enforcement Administration had already imposed an "emergency" ban on some of the stimulants used in bath salts, and so had the Florida legislature. But Miami-Dade County commissioners apparently deemed those measures inadequate, because they approved their own ban just two weeks after Eugene attacked Poppo. Congress enacted a broader federal ban on June 27, 2012, the same day it was revealed that bath salts had nothing to do with Eugene's crime. Prior to that vote, the main sponsor of the bill, Rep. Charlie Dent (R-Pa.), had expressed the hope that skeptical colleagues would change their minds "when they learn about this face-chewing situation in Florida," that "this terrible tragedy…will bring about greater awareness and accelerate the need to enact meaningful legislation that will protect people from this poison." It sure looks like that's what happened.

Support for these laws was based on a grossly distorted view of how people act after taking bath salts. "The description of bath salts present in these broadcast media reports was very different from the scientific literature on the topic," Swalve and DeFoster write, "and it does not appear that the media took this particular source of information into account in reporting. The primary symptoms mentioned in the transcripts included an increase in aggressive behavior, 'super strength,' and vivid hallucinations that could cause psychosis. This represents a marked difference from the increase in talkativeness, empathy, energy, and euphoria that characterize the clinical literature on the effects of bath salts." While the research indicates that the most commonly reported effects of bath salts are improved mood and heightened energy (which explains why people like them), TV reports "focused overwhelmingly on psychosis, paranoia, cannibalism, and other extreme outlier behaviors."

To reinforce their depiction of bath salts as catalysts of mayhem, reporters covering the "Miami cannibal attack" cited other examples of violence allegedly caused by the stimulants. "Other cases that were 'packaged' with the Miami incident," Swalve and DeFoster note, included "a case in which a man ate someone's brain, a man who stabbed himself in New Jersey, and the dismemberment of a porn star by her boyfriend." Yet "none turned out to actually have involved the use of bath salts." In that respect, of course, those cases did resemble what Charlie Dent called "this face-chewing situation in Florida."

Despite all the references to a bath salt "epidemic," these drugs were never very popular, and it seems use of them was already declining when CNN et al. warned that it was on the rise. Swalve and DeFoster note that calls to poison control centers involving bath salts fell from 6,138 in 2011 to 2,654 in 2012. The sensational reports provoked by Eugene's gory crime either ignored or blatantly misrepresented these data. "In a June 2 broadcast on CNN," Swalve and DeFoster write, "a guest noted that 'about two years ago, there were 300 reported cases, last year 6,000, and this year 1,000 reported cases, so it's on the rise,' with the news anchor echoing this sentiment, seemingly oblivious to the contradiction."

Journalists' general tendency to hype drug hazards is amplified by the sources on whom they typically rely: cops and clinicians whose work brings them into regular contact with a highly skewed sample of drug users—the ones who end up in jail or in the hospital. In this case the main sources were Armando Aguilar, president of Miami's Fraternal Order of Police, who speculated early and often that bath salts turned Eugene into a face-chewing zombie, and Paul Adams, a local emergency room physician who was happy to back Aguilar's claims about these drugs' impact on strength and aggression.

Aguilar told ABC News there were "striking" similarities between Eugene's assault and incidents involving bath salts. "The cases are similar minus a man eating another," he said, which is like saying Fifty Shades of Grey is like Cinderella except for all the kinky sex. "People taking off their clothes. People suddenly have superhuman strength. They become violent, and they are burning up on the inside. Their organs are reaching a level that most would die. By the time police approach them, they are a walking dead person." In my book Saying Yes, I talk about "voodoo pharmacology," the idea that certain drugs take control of people and force them to do bad things. Here you have a literalized version of such zombification: a drug that turns you into "a walking dead person" who feasts on human flesh.

"You can call it the new LSD," Adams told ABC News—a mystifying comparison, Swalve and DeFoster note, since LSD and synthetic cathinones "are clinically dissimilar in terms of the behavioral effects and pharmacology." Maybe Adams meant that "you can call it the new LSD" because people are freaking out about it based on misinformation. But probably not. Patients under the influence of bath salts "seem to be unaware of their surroundings," he continued. "They are not rational, very aggressive and are stronger than they usually are. In the emergency room it usually takes four to five people to control them." In a Daily Beast story that appeared the same day, Adams said it sometimes takes "seven security guards and one doctor."

The doctor later told Playboy he did not actually confirm that the patients he was describing had taken bath salts. "If I want to test for bath salts, I have to send samples to an outside laboratory," he said. "When somebody tests negative for everything, it's a good bet bath salts are involved." Just like it was a good bet that bath salts were involved in the attack on Ronald Poppo?

News organizations eager to maximize eyeballs have little incentive to question the testimony of alarmists or seek a calmer perspective, so they end up echoing the warnings of their sources. In a story quoted by Swalve and DeFoster, for instance, ABC News correspondent Matt Gutmann, drawing on a common theme of yellow drug journalism, reported that bath salts impart "superhuman strength" and "immunity to pain," creating formidable threats to police officers: "Bloody, naked and hallucinating, they fight their demons and anybody near them, walking through bullets, snapping off taser prongs, growling like caged animals." Swalve and DeFoster sum up the tenor of the press coverage this way:

An early focus on bath salts, triggered by a series of speculative quotations from a single law enforcement source, fueled a month-long focus on bath salts use as the sole interpretive schema for the Miami attack, shutting out other possibilities from coverage. Most glaringly, discussion of mental health as it may intersect with and affect drug use was completely absent from coverage, an oversight that is particularly problematic because it is now clear that mental illness was likely a more appropriate (albeit less sensational) interpretive schema for this incident.

I'm not sure that "mental illness" is any more satisfying or scientifically rigorous as an explanation for Eugene's behavior than bath salts were. But it should be obvious that idiosyncratic factors of some kind must be at work when someone does something so unusual and shocking that it attracts international press attention. Even if Eugene had taken bath salts, that fact alone could not possibly explain his actions, which were extreme even for the minority of consumers who react badly to these substances.

"By relying on inflammatory fear-based appeals; focusing on outlying behaviors; omitting more likely alternative explanatory cultural, environmental, and social factors; ignoring additional sources of data; and 'packaging' unrelated events together to bolster claims about a dangerous 'epidemic' of bath salts use," Swalve and DeFoster write, the news organizations whose work they analyzed, "which are expected to be subject to high ethical standards, presented a portrait of this Miami attack—and of bath salts use in the United States—that was misdirected and disconnected from current clinical research on the use of the drug." In fact, they continued to do so even after the purported link between bath salts and the Miami attack had been decisively debunked. As late as a year ago, CBS News was still citing Eugene's crime as an example of what people do under the influence of synthetic cathinones.

The same hyperbolic tendencies that Swalve and DeFoster saw in stories about the Causeway Cannibal can be seen in prior coverage of drugs such as marijuana, LSD, PCP, crack cocaine, methamphetamine and salvia, not to mention subsequent coverage of drugs such as Krokodil, Captagon and flakka (another name for alpha-PVP, one of the stimulants used in bath salts). All of those panics have been accompanied or followed by critiques like Swalve and DeFoster's, pointing out the gap between the horror story and the reality. How many times must leading news outlets fail to live up to their supposedly "high ethical standards" before we conclude that those are just as mythical as tales of drug-induced cannibalism?

This article originally appeared at Forbes.com.