What’s the safe word?: A look at the dark trade in rare toxins

Forensic detectives found at least five types of poison in Lin’s blood, including mercury and tetrodotoxin, a neurotoxin typically derived from puffer fish.

It turned out that Xu had spent months preparing. He bought small quantities of more than 100 poisons on the dark web, and tested them (brace yourself) on dogs and cats in a makeshift facility in Shanghai, before he fixed on the cocktails he eventually used to kill Lin.

As toxins become easier to produce in homegrown labs, and easier to distribute via the dark web, less successful attempts make news from time to time. Often, they come to light via the US Federal Bureau of Investigation. FBI teams have taken to trawling the darker recesses of the dark web, posing as poison-sellers themselves.

In 2019, Janie Ridd from Utah tried to buy a deadly antibiotic-resistant bacteria from one such squad. She later confessed she planned to use it on her best friend, because she wanted custody of the friend’s son. The FBI team delivered a package containing some harmless compounds in petri dishes, and then arrested her.

In 2018, Jason Siesser from Missouri was caught in a similar way, trying to buy three vials of dimethylmercury; enough to kill 300. In 2015, Mohammed Ali, a software programmer from Liverpool, tried to buy enough ricin to kill 1,400 people. He too was caught by the FBI, operating undercover as sellers.

Lethal tender

Poison is not a common murder weapon.

Crime statistics for the US indicate that most murders are carried out by men, using a gun, while less than 1% of murders are acts of poisoning. Women, when they do kill, reportedly use guns about half the time; followed by knives; followed by large, heavy objects. Poison currently comes in sixth on this list.

Where it is popular is in assassinations. Russia has long had a state-run poison-factory, set up in the early 20th century by the founding head of the Soviet Union, Vladimir Lenin, as part of the Kremlin’s massive chemical and biological weapons programme.

The US of course has changed the world with its experiments in these areas, but theirs aren’t referred to as poison factories; they are “research establishments”.

Russia has been known to do one thing the US has not been proven to do: use its poisons to silence voices of opposition and dissent.

In 2020, the now-late Russian opposition leader Alexei Navalny started screaming in pain on a flight to Moscow. The plane made an emergency landing and he was airlifted to a hospital in Germany, where he was in a coma for two weeks. He is believed to have been poisoned with a toxin from the novichok family of nerve agents, developed in Russia. He eventually recovered, returned home and continued his work; was arrested, jailed, and died of unclear causes while in prison, in February this year.

In 2006, the Russian defector Alexander Litvinenko was killed using a radioactive cup of tea. The European Court of Human Rights ruled that the Russian government was responsible.

In 2023, a pro-democracy advocate and founder of the Free Russia Foundation Natalia Arno was suspected to be have been poisoned with a nerve agent in her hotel room in Prague.

Poisons have been used to assassinate for thousands of years. Through years of war, peace, unrest and annexation, governments have handed out fatal compounds, complex chemical mixes, nerve agents and biotoxins for use against perceived enemies. Civilian killers have typically had to coerce doctors, chemists and pharmacists to help with sourcing.

Doorstep service

The ideal poison is odourless, tasteless, fast-acting, and causes symptoms that are similar to natural causes of death. Different poisons do this in different ways: by affecting body temperature or heart rate, interrupting breathing, or causing nerve damage.

The ideal poison is also untraceable and incurable. These last two are now all but impossible to achieve.

“Highly sophisticated instrumentation is available to detect the minutest quantities of toxic substances,” says OP Jasuja, professor of forensic science at Regional Institute of Management and Technology (RIMT) University, Punjab.

Perhaps for this reason, the market for toxins on the dark web is small, particularly when compared with the unceasing demand for the big four: drugs, weapons, financial information and child pornography.

Another reason for the small market could be that there are simpler ways to acquire a toxic substance. Most of us have at least a few at home: household detergents, insecticides, pesticides, antidepressants and sedatives.

It is still alarming to think that a package in the mail could be making its way to someone’s door, full of a toxin made in a lab, ordered off the internet’s dark cousin.

Imagine opening it; knowing someone in your home placed the order. Then hearing, “I told you not to interfere with my deliveries, dear. Now let me see if I can find the number for a good doctor…”