Okay. Is your girlfriend conscious?
Yeah, she's-
Is she all right?
Yes. Shes' [inaudible 00:00:12], because-
Okay. So, what makes you think somebody poisoned your food?
Because, she was my ex- girlfriend. She came to visit my home.
You think your ex- girlfriend's done it.
Yes, sir.
January, 2009. A West London man and his fiance sat at their dinner table to share a meal. And to discuss their wedding planned for Valentine's Day. Just hours after he made this 999 call. Lakhvinder Cheema was dead and his fiance critically ill. The dead man's suspicion lay with his spurned ex- girlfriend. But where was the proof that this mother of three was behind the plot?
Aconite poisoning is extremely rare. And indeed, a lot of doctors haven't even heard of it before. Let alone know what its effects would be or how to identify a poisoning of this case.
Today we'll find out what happened when Kew were called upon to help catch a killer.
You have this very sophisticated equipment. That allows us to have this fingerprint of the chemicals.
I'm James Wong, and you're listening to Unearthed: Mysteries from an unseen world. From Royal Botanic gardens, Kew. Lakhvinder Cheema was known to his friends as lucky. He and his girlfriend Gurjeet Choongh, were busy planning their wedding. Choongh was 21. And had been in a world in relationship with exciting times ahead. But early in their engagement. Choongh had
made an unexpected discovery. A woman called Lakhvir Singh, revealed that she and her fiance had been lovers for 15 years. Lucky had ended the affair. But his ex lover had been heartbroken sending messages that became increasingly more abusive. But was this a motive for murder? Lakhvir Singh, was a mother of three. Her husband was suffering with cancer in hospital. In January, 2009. Singh went to Lucky's house
in Feltham. And was let in by the lodger. Who saw her go into the fridge and take out a container of Curry. It was this Curry that lucky and his fiance were to later eat.
And what makes you say somebody poisoned your food?
After symptoms has started to appear. Lucky's sister and nephews helped get him and Gurjeet in the car to West Middlesex Hospital. But within hours he was dead. Gurjeet was placed into a medically induced coma, while scientists sought to identify the substance. This ultimately saved her life.
I'm Luke Smith. I am a consultant in acute medicine, with an interest in toxicology. We see a lot of things like paracetamol poisoning, alcohol poisoning, things like that. Aspirin, occasionally carbon monoxide. In terms of plant poisonings, not as common, but still we do see things. Plants generally tend to produce a lot of chemicals which have effects. And
it depends on how you define plant poisoning. For example; cocaine itself would be a plant poison in its truest sense of the word. So, we see quite a lot of that actually coming in into St. Thomas's hospital anyway. Aconite poisoning is extremely rare. And indeed, a lot of doctors haven't even heard of it before. Let alone know what its effects would be or how to identify a
poisoning of this case, in a poisoned patient. In this particular case, the poisoning was so severe that the evolution of symptoms was very rapid and the patients became extremely poisoned, extremely ill, very quickly. So much so, that the timelines involved were so short that identifying the patients had even been poisoned was a tricky one in itself. Cheema,
who was the gentleman who died. Suspected he'd been poisoned and told the ambulance crew that when they called in the ambulance. So, we had it in the back of our minds that this might be a possibility. But because they deteriorated and he died so rapidly, there was no time to identify what the agent was. It was very interesting because it is such a rare poison, particularly in the Western
world. In India it's more common. And it's also used as a herbal remedy in Chinese herbal medicine. But it's virtually unheard of in the UK or in America or the Western world. From a physician point of view. The whole goal of treatment in this particular case would be
to try and save the patient's life. So, we would have an algorithm that we have drummed into us from medical school about how to approach acutely unwell patients, whatever is wrong with them. And it's to stabilize each individual body system in turn to prevent the patient deteriorating or dying. It's called the ABCDE approach. That is what we the doctors looking after these patients would have tried to
have done in the first instance. So it wouldn't necessarily have been about identifying a poison or an agent in particular. It would be to try and save their lives.
Proving a clear connection between ex- girlfriend Singh, the Curry and the toxin that killed lucky wasn't straightforward. The first challenge was to identify the toxin scientists tested for nicotine and arsenic, but have ruled both out.
Police were called and the National Poisons Information Service were called. Who gave advice on what were the best tests to do to try and identify and as yet unknown poison and what tests could be sent off. So, things like contents of the stomach, a postmortem could be sent, blood samples could be taken. And we have to make sure that we take the right blood samples. And they're
in the right blood tubes. And given this is a legal case. There has to be a chain of evidence and a chain of custody observed as well, to ensure that any evidence that is secured and in identifying the poison can be used in a court of law as well. Lots of poisons don't have specific antidotes. And treatment is supportive, rather than trying to find an agent to
counteract the effect of the poison. So, the approach from the National Poison Service at the time, would have been similar to any unknown poisons to just try and save lives. But it would have been important that they had in the back of their minds as well. We need to find out what this was because this has legal implications. And we need to think about what samples we need
to be collecting and how we do that. The main presenting symptom they had initially was vomiting. And that's quite a nebulous and ubiquitous symptom. But they progressed rapidly in their poisoning. They then developed pins and needles in the face, particularly around the mouth and then extending to their hands as well. And that became quite disabling to the point when they weren't able to use things like telephones and
things like that. They also then developed visual disturbances and ultimately Cheema lost his ability to see quite rapidly. That led on to muscle weakness, into changes in sensation in the limbs. But the most significant from a medical point of view effect of the poison, was what it was doing to the poisoned patient's hearts. We can see that they
develop multiple arrhythmias of the heart. The electrical activity of the heart was massively disturbed such to the point where particularly in Cheema, it was unable to sustain the mechanical ability of the heart to pump blood around the body. This happened very rapidly. We're talking about between 60 to 120 minutes after poisoning. The severe symptoms of poisoning occurred.
Aconite poisoning in particular is interesting because it has an unusual mechanism of poisoning at the cellular level. It's relatively unique. Other plant poisons, which have similar effects work in different ways. Things like mandrake and hemlock work in slightly different ways. They tend to block electrical signals, whereas Aconite tends to increase them. And that's an unusual mechanism of
action. And it's also arguably harder to treat. It also tends to have similar effect to nerve agent poisoning as well. A lot of the symptoms you see are similar to those that you would see in nerve agent poisoning. And indeed, some of the chemicals in the Aconite plant actually do work in a similar way to nerve agent
poisoning. They block an enzyme called acetylcholinesterase. Which ultimately leads to the same symptoms that you would get in nerve agent poisoning. It's also an incredibly rare poison. Which makes it interesting by very into its nature.
Few people have heard of forensic botany. A discipline that can stretch from the analysis of clues left in traces of ancient pine grains, to the information coded in tree rings. Whether it's a detailed understanding of the makeup of aquatic environments, to the chemical composition of soil, to the hidden rules of how ecosystems work. Knowing what to look for is
half the challenge in helping investigators solve mysteries. It is here onsite at Kew, that scientists are able to help investigators solve their mysteries. I met professor Monique Simmonds, [ OBE to 00:09:33] to find out more
I'm Monique Simmonds. And I am Deputy Director of Science at the Royal Botanic Gardens, Kew.
Believe it or not, the tiniest samples can offer vital clues and evidence in a number of situations. Monique explained how plants can leave their trace, even when a perpetrator doesn't.
Plants can be used in so many ways. They can be used to identify a scene by what could be on say, a pullover, the victim's clothes, their shoes, in the grooves of the shoes, the seeds, the particles. They can often identify where a crime took place. And then you've got how it's possibly being used if it's a plant toxin. So, different aspects of botany can assist with
where plant took place. And possibly if a plant was used. Which plants and therefore, where it could have come from. So you can use it in different ways. But you need to have that basic botanical knowledge. Depending on the role that the plant plays, you'll need to have
different aspects of plant science coming into it. So, pollen or even the hairs on the back of a leaf of a plant that can cling to your clothing can be preserved for many years.
Plants can't run away or hide from threats. So they've had to evolve a different evolutionary strategy. In the form of toxic compounds that can act as a defense mechanism. Monique and her colleagues were brought in to help identify the mysterious poison when events were still unfolding. Police suspected murder, but the evidence Kew could provide would help them find the answers.
Initially when they got the emergency telephone. Then when they got the two patients into hospital. There were some common characteristics. And that was blurred vision, numbness, a very shallow heartbeat. And that indicated some form of toxicity. So they rule out the usual things that could be associated like arsenic, et cetera. The patients didn't have some of those
characteristics like diarrhea and other things. So it looked like it was having an effect on the nervous system and that leads you to possibly plant based poisons. And some of these that are known to affect the nervous system can be alkaloids, a group of chemicals from plants. That are known to cause effects on the nervous system. But, at that stage, they couldn't detect them. Because we'd already done
work for the National Poisonous Unit. Some of those involved, knew about some of the work that we've been doing at Kew.
At this stage information was strictly on a need to know basis. The symptoms had led scientists to look at aconitum, which you might know as monkshood or Wolf's bane.
We were asked to see if we could assist with a toxicity. So we hadn't got a lot of background information other than the fact that the people involved in the case thought that toxicity could be associated with alkaloids that come from aconitum species. But their test should show that that wasn't the case. We were not told anything
about the victims or how this had happened. We were just asked if we could identify these because they're associated with a potential murder case. Then you get more details as you guided through. So, sometimes they don't want to totally lead you. We're usually not told everything. Because they want to have some form of independence. So, it's gradually revealed to us.
In any poisoning case, it's a race against time to identify the chemical toxin that caused the symptoms.
If you can have a knowledge about what the plant is and the toxin associated with that adverse response. Then that's where the medical profession can be more accurate in the form of antidote that there will use because many of those antidotes are pretty strong in themselves. And sometimes it can be very dangerous to use the wrong material.
You can cause more problems. But if you can have it really directed by an accurate identification of what the toxins are that can assist greatly. The ability of having a real professional in, member of my team, or it's with Jeff Kite. To be able to get that really accurate analysis done at each stage is really a key to
solve this issue. So it's like having a unique botanical fingerprint of that particular sample that could be followed.
Monique explained how samples were released to Kew for testing as the investigation and the questions evolve.
So was it aconitine or is it a related species? So at that stage, we didn't know all the details. That only became clearer later on. They said they be able to send us some samples of the blood or samples from the digestive track of one of the victims. And then the Curry. Could we look at the Curry? And then they said that they had got some leaf powder from a bag that
had been found in Mrs. Singh's Pocket. And we said, " Well, we'll start off on that one. That would be the easiest thing. If you think there is a link."
Thanks for listening to Unearthed. I'll be back again in just a minute. But first here's a message from our supporter, Kim Cattrall.
As a charity, the Royal Protonic Gardens, Kew is facing a severe funding crisis, right now. The impact of Corona virus has created a financial shortfall of 15,000, 000 pounds. This money is vital for the upkeep of these beautiful Botanic
Gardens. And crucial to continuing its global conservation work. Plants and fungi hold many of the answers to the world's biggest challenges such as climate change, food security and biodiversity loss. And Kew needs to play a role in furthering the science and identifying desperately needed solutions. If there's one
positive thing that could come out of this pandemic. It will be to encourage each and every one of us to look a fresh and with urgency at these global challenges. If you are enjoying this podcast and feel inspired by the work that Kew does. Please go to Kew. org to donate today. To help not only protect Kew, but also preserve the future of our planet.
Because we understand the processes behind plants. It's possible for the team at Kew to work with a wide range of samples in forensic cases.
Yes, we have an idea because of work that's been done on the, by synthetic processes of these plants. And sometimes have therefore that they can be broken down. Now, if we get something from the gut. It may be that it hasn't been totally digested. So, sometimes it's easier to be able to identify a plant matter in the gut. It will depend on what part of the gut. In some
cases we will get the blood samples. If that is the case, then we need to know what are the breakdown components associated with the particular plant metabolites. In this case, we didn't need to go as far as that. Because we could link what had been found in the pocket. What had been found in the Curry. What had been found in the samples that were found in the fridge.
And then in the stomach contents. If had it been later on, we might not have been able to do it. But unfortunately, it was a very short time before the victim died in this particular case.
So what did they find?
Some people wouldn't realize at Kew, that we'd have this very sophisticated equipment that allows us to do the chemical work. And that's done by a method called liquid chromatography- mass spectrometry. That allows us to have this fingerprint of the chemicals. We could see that there were 19 alkaloids in the sample. Now that's quite complex. But one of them was in high amounts. And that was [ pseudo I-carnitine 00:18: 48].
Pseudo I- carnitine, an extremely toxic alkaloid chemical. Is found within the roots of a plant known as Indian monkshood or aconitum ferox. This discovery was absolutely key in understanding what had happened. It hadn't shown up in previous tests simply because the scientists didn't know to look for it.
Now, that is something that the previous people hadn't spotted. Now, why we had it on our database. Is the fact that we had previously dealt with some toxicity problems associated with this plant material. And this plant material we thought, it actually doesn't come from a British plant. It's a possibility it comes from a Indian plant and that we were able to put the pieces of the jigsaw together. So,
once we got the chemical fingerprints. We could then go back from the material that been found in the pocket to look at the Curry. And we could see that the Curry had a similar type of profile. And then we could link that to the victim. You need to know what to look for. And then the methodology that
would enable you to detect it. Because in some cases, there aren't commercial libraries that have all the ingredients saying that could be potential toxics. You have to build those libraries up. Which is one of the things that Kew has been doing. And of course, the other thing that we have at Kew. Is knowledge about the uses of
plants. Now, some of those could be bad uses I. e; plants that are known to be toxic and possibly have been known to be used in homicide. And we collect that type of information. So we just knew that historically, some plants have been used in India for homicide. And just having that knowledge enables us to sometimes make those links. Especially, when we have knowledge about the symptoms
that the person has, who died. So we can put the bits of the jigsaw together
When it came to the Curry Killer Case. Establishing what the mysterious substance was. Was not only key in the race to find lifesaving treatment, but also in seeking justice. That unique plant fingerprint allowed Monique to establish the species and possible origin of this plant. This intern shed further light on events.
When we thought, Oh right, this is a plant that comes from India. Or let's say, that part of Asia. It's kind of Bangladesh, India, Pakistan, that kind of area. Is it possible that she'd visited or it could have been that she got it from a herbalist. But you're thinking maybe not. Of course, that becomes important. You could show that this had been planned.
Aconitum is a notoriously toxic genus containing over 250 species. You might have heard it's common names like devil's helmet, monkshood, or wolfsbane. Yep, it's that mysterious plant mythologized by [ Arvid Keats 00: 22:22]. And of course your favorite Teen Werewolf novels. It typically has blue purple hooded flowers. But there's quite a lot of variation across the genus. The alkaloid toxin it
produces aconitine, is notoriously difficult to detect. In fact, the last time an English court convicted anyone of using the poison, was in 1882. When a doctor called George Henry Lamson used it to poison his brother- in- law. It's a fast acting neuro and cardiotoxic. And victims appear to have asphyxiated.
Monique explains a little more about the history of the species we're familiar with in the UK and it's cousin aconitum ferox
Often it hasn't been used in a bad way. It's known to contain poisons. The other bit of the story is the fact for a long time, in the past it had been used. Because it was actually very difficult to detect these types of compounds. So, people have got away with using some of these plants as toxins. Because the investigators hadn't got the ability to detect it unless they found the
plant material had been used. So, this was a species called ferox. That comes from India this had been used in the case. So it's not the British species that's often goes under the name of Wolf bane. So it's an example you could say of 19 century methods being detected by 21st century techniques. We've advanced in our ability to detect toxins that we would not have had in the 19th and earlier 20th century.
I asked Monique what we knew about the modern users of this species of aconitum ferox in India.
It is used sometimes as a medicine in low concentrations. And sometimes it will be therefore used if it's a trained herbalist. It will be used say, to clear the body. And sometimes it's used for anti- inflammatory conditions. But it would only be used for very short time. It's sometimes also used in treatment of eye problems. But in
the hands of a real professional herbalist maybe okay. But sometimes they don't fully know enough about the plant to be aware of some of the problems associated with continual use. People should think twice about using some of these plants. They had tried to put evidence like this together. And it doesn't always work because you only have part
of a story. I think in this particular case, the police were able to link the fact that Mrs. Singh had been over to India in a potential had got some material. She was in possession of the raw material. Was evidence that it was in the Curry, there's evidence that that Curry was then used as part of a meal, with the two people that suffered. And the fact that we could then link that with one of the
victims. So, if we could put every bit of the stage together. Enabled the police to have a pretty solid case. And then we found out afterwards that evidently there was an attempt before.
The evidence gathered including Kew's vital findings. Were enough to convict a murderer. The judge, Paul Worsley at the Old Bailey condemn Singh's actions in court.
You are not just a spurned lover. You did not simply explode in anger at your rejection. You set about a cold and calculating revenge.
For the first time in decades. An Aconitum murderer was behind bars. This calculated murder didn't only have an impact on the lives of Cheema's family and fiance. The investigation broke new ground for how Kew collaborates with authorities. I asked Monique how the pace of the investigation has caused her and others to reflect on how such cases are
handled moving forwards. Perhaps a new methodology might even be useful in other forensic processes.
We're hoping to increase the amount of knowledge about DNA that would be able to be used. We're also very keen on crime associated with the trade in endangered species. And that will be recognizing timber that is from endangered plants, to make sure that only appropriate timber gets used in different forms of timber trade.
Kew is an invaluable resource in investigating unknown poisons. Because when you exhaust your list of common poisons. You have to start looking at the rarer things. Often plant- based poisoning does tend to be the second or third line chemical, which people fall back on when they're either poisoning themselves or poisoning others. And we end up having to look for rarer poisons, which are known to have significant
effects. And the plant world generally tends to provide those chemicals quite frequently. So, Kew is an invaluable resource in testing samples and being able to compare chemicals that we identify at post- mortem or in blood samples in the living patient with chemicals that they have isolated from plants.
They're also an invaluable resource, when we are identifying a poisoning or trying to exclude a poisoning in patients in whom we know that they've actually ingested a plant itself. So we can actually compare what we have to, what they have on their records. To identify whether it truly is a poison or not. An example of that would be hemlock, which is poisonous in the UK and cow
parsley, which has not look very similar. So, it's useful that they can identify the two different species and be able to tell us whether what has been ingested is actually toxic or not.
Next time on Unearthed from Royal Botanic gardens.
80% of people in Papua New Guinea live in rural areas. And when we say rural, we don't really mean people driving around in land rovers in Devin. We mean people living right out in really hard to access areas.
We'll find out how plants from around the world have been used locally exported and exploited as medicines. By harnessing the properties of plants all the way from forest to pharmacy. Social history has been changed. Ecosystems, reshaped and communities transformed around the world.
Some Indigenous tribes in Northern Ecuador, they use species of (inaudible) as a contraceptive.
Make sure you don't miss it by subscribing on your Podcast App now. You can share this episode with the # KewUnearthed and follow @ Kewgardens on social media. I'm James Wong. Thanks for listening.