Eighty-five years ago, a Florida murder began a moral panic about marijuana use. On October 16, 1933, 20-year-old Victor Licata took an axe and killed his parents, brothers and sister while they slept.

The newspapers claimed Licata committed the crime while crazed on marijuana. This seems strange today, when whatever the risks of marijuana, it’s not generally believed to turn people violent. But the response to Licata’s crime followed a pattern that would be repeated in decades to come with other drug scares.

Licata’s murder kicked off the passage of more draconian anti-cannabis laws. Licata’s case was even referred to in Congress, during the passage of the Marihuana Tax Act of 1937. (Marijuana was actually available on prescription in the US until 1941). Part of the anti-MaryJane campaign was the film classic ‘Reefer Madness’, designed to scare kids straight with its tale of suburbanites turned violent.

Of course, marijuana stayed around. Its rise in popularity after the 60s meant people associated it more with hippies than killers – and the idea that it put people at risk of anything more than the munchies became harder to sustain. The argument then became that it was a ‘gateway drug’ to harder stuff (a concept that remains controversial).

Meanwhile the moral panic machine moved on to other drugs. From the Seventies, one of the menaces was LSD, had a memorable role in urban legends, such as the story of horrified parents who come home to find the babysitter has put the baby in the oven thinking it was a turkey.

Hot on its heels came PCP, or ‘Angel Dust’, which made users violent and deranged. In the 1980s, it was crack, and by the 2000s it was meth. Whatever the drugs, there will be stories of those under its influence behaving violently, sometimes even with superhuman strength. The idea of chemicals that turn human beings into monsters is an ancient trope, and one that modern drug scares easily echo.

In more recent years there has been a scare about ‘bath salts’. Stories first started appearing around 2010, referring to users as ‘zombies’. Global attention came with a horrific cannibal attack in Florida in 2012, in which a naked man was apprehended while eating another man’s face.

According to a police officer who attended the scene, people in drug psychosis ‘have all taken their clothing off, been extremely violent with what seemed to be super-human strength, even using their jaws as weapons.’

In fact, later toxicology results found no trace of the bath salts in that attacker’s system, but there was a further spate of cases in which bizarre and aggressive behaviour was chalked up to the drug.

Biting seems to be a particular theme: One user bit a police officer, while another even bit a police car.

Meanwhile, marijuana has been tamed – now seen as potentially useful for some medical conditions, and at any rate not worth the harsh punishments meted out for more ‘serious’ drugs. Medical marijuana is increasingly available since the 1990s, and the push to legalise has moved beyond just ‘liberal’ states. Proposals to legalise medicinal marijuana are on the ballot next month in Missouri and Utah; Michigan and North Dakota will vote on legalising recreational use. Many people now view marijuana as no more dangerous than alcohol, and don’t want its users to be punished for a relatively harmless habit.

But was it entirely wrong to link Licata’s crime to smoking reefer? Maybe not.

Studies have shown connections between cannabis use and the development of schizophrenia and other psychoses.

People with certain genetic predispositions are particularly at risk of psychosis, so marijuana may be contributory rather than a sole cause, but heavy use seems to be strongly correlated.

Licata was found to have a pre-existing mental illness (schizophrenia ran in his family), and was found unfit for trial. So it’s possible he was one of those who was adversely affected by marijuana use. (He was remanded to the Florida State Hospital for the Insane and later committed suicide).

Nonetheless, the scarcity of studies means there’s a lot we still don’t know. The illegality of marijuana in most Western countries for the last 60 years has limited options for research into its usefulness as a treatment as well as its risks. (Much of the evidence for medicinal cannabis is anecdotal rather than the result of controlled trials). Perhaps in the next few years we will learn more.

But we’re sure to find another drug to demonise, and blame for extreme crimes.