Serial killers, and sails on supertankers

Plus, we hear about water voles' return to the Lake District...
25 August 2023
Presented by Chris Smith


In the news this week, how can we understand the motivations of serial killers? Also, we ask a dermatologist to outline the early signs of melanoma, and find out about the initiative to reduce carbon emissions from the shipping industry using aeroplane wings. Plus, water voles are being reintroduced in the Lake District - we hear from the site manager in charge.



In this episode


00:50 - What motivates a serial killer?

We speak to a criminologist about the case of Lucy Letby...

What motivates a serial killer?
David Wilson, Birmingham City University

Judge - Lucy Letby, on each of the seven offences of murder and the seven offences of attempted murder, I sentence you to imprisonment for life. Because the seriousness of your offences is exceptionally high, I direct that the early release provisions do not apply. The order of the court, therefore, is a whole life order on each and every offence, and you will spend the rest of your life in prison.

Judge, Mr Justice James Goss, sentencing British nurse, Lucy Letby, who was found guilty of killing and attempting to kill multiple newborns in northern England.

Much of the commentary on the case has dwelled on why Lucy Letby did what she did. But David Wilson, professor emeritus of criminology at Birmingham City University and a leading authority on serial killers, argues that getting inside the minds of serial killers is unhelpful. Instead, he says, in trying to reduce the risk of a repeat, we should focus on who their victims tend to be and the environments in which they tend to operate…

David - Most of my research has been trying to explain that serial killers reveal vulnerabilities in society which allow them to continue to kill for the length of time that they do and Letby was an outlier. In terms of the research I've conducted about nurses who'd kill in a hospital setting, most of whom, according to my research will be caught within three months, she was able to avoid detection for 12 months. And the vulnerabilities surely that Letby reveals is that she didn't have horns on her head. She was seen as nice Lucy Letby, and that therefore meant that alarm bells didn't ring quickly enough or for long enough to stop her from killing.

Chris - You said in a piece you wrote for one of the broadsheets earlier in the week that like most of the serial killers I've worked with and studied, Letby's been silent about what might have driven her to kill. But what detectives have produced, which is quite intriguing on searching her house, were pages and pages of notes all about what her motivations were, et cetera. Is that unusual?

David - It's unusual, and nor do I find it particularly significant. I've read most of those notes and I didn't find them particularly compelling in revealing what might have been a trigger for her wanting to kill. It seemed to me that every serial killer I've worked with or studied either is very silent and uncommunicative about their motivation, or indeed one particular serial killer I worked a great deal with. We talk endlessly about his motivation, but not necessarily with any great insight or indeed offspring any help in thinking through what one should do to stop similar serial killers. So I find the whole motivation question for me is one that is obviously intriguing to many people, but ultimately isn't going to allow us to really think through what we should be considering about stopping other nurses in a hospital setting from killing vulnerable patients.

Chris - Are the media and to a certain extent also books and novels and films and TV and so on, are they being a bit misleading then because they're almost using 'getting inside the mind of a serial killer' and all that kind of thing as a plot device in order to move the narrative on or or to create that sort of tension that makes it watchable and in fact, that is not, you're saying, how these guys tend to operate?

David - That's absolutely correct. As far as I am concerned and indeed I've spent an entire career, I think, having an academic and an interpersonal debate with FBI profilers who are constantly trying to get into the mind of a serial killer. And I keep arguing, well, I've spoken with many, many serial killers and either they're quiet or they talk endlessly but don't tell me anything. And so it's far more important, it seems to me, looking at the groups who are vulnerable to attack.

Chris - What do we do then about making the situation safer without, at the same time, the burden of overregulation? A number of doctors have been interviewed on this subject and they've said, look, in the wake of what happened to Harold Shipman, there was a very strong reaction to regulate the medical profession. Many people say none of what doctors are now going through in terms of annual validations and so on would catch Harold Shipman if he was still operating today.

David - I think that's a fair point. I also think that it's important to bear in mind that the research that I conducted with a colleague about nurses who are going to kill in a healthcare setting from the 1970s through to the mid 20 teens, worldwide, we found a total of 16 such nurses. Now that tells you this is a very, very rare phenomenon and therefore the chances of it happening again are also incredibly rare. It does seem to me that she continued to kill for longer than those nurses that would be part of the sample that I uncovered who were, by and large, caught within three months. And that does take us back into why red flags didn't fly and fly for longer in her case. And that has to do with the fact that she was very well integrated into her team. She didn't make them feel uneasy. She had appropriate qualifications. She didn't seemingly spend two inappropriate amounts of time talking to the families of the babies who had died, killed by her. But at least two of the consultant paediatricians alerted the hospital managers to their concerns about what was happening to the neonatal unit and no action was taken or action wasn't taken until it was too late. Now, there has to be a lesson that's learned from that - hospital managers should have taken seriously what a number of paediatricians were saying about the spikes in death, which were significantly higher than the previous year before Letby started to work on the neonatal unit.

Chris - But what you've just said is almost the same as when a person goes through various disclosure and barring checks, for example, to see if they have some kind of criminal past that they've swept under the carpet or kept in the closet. A lot of these tests and things assume that someone comes with a pre-made track record that you can find that discloses them as a problem. Many of these people come with a clean bill of criminal health and they're going to look like shining examples of practitioners.

David - Well, that's really interesting that you say that because that's actually not what my research uncovered at all. Of the 16 nurses who killed in a hospital setting, virtually all of them had some kind of problematic history in a previous unit, and often they were moving on precisely because they were making people in that unit or that hospital feel uneasy. And one of the main messages of the research was that hospital administrators had to take up their references, the references of people, nurses who were moving from one hospital or one unit to another, and who were moving regularly because they were making people uneasy. But there was such pressure in the healthcare systems that the temptation was not to take up their references because those administrators were just simply so grateful that they had got a pair of hands to fill the vacancy. And so some of the basic things still need to be done, it seems to me, and therefore, rather than thinking up clever and evermore bureaucratic processes, maybe what we've just got to do is do the basic things correctly.

Skin close up

09:38 - Melanoma: causes, identification and diagnosis

Chris Evans' health scare provides a useful reminder to get changing moles checked...

Melanoma: causes, identification and diagnosis
Julia Newton Bishop, University of Leeds

The British broadcaster and DJ, Chris Evans, has revealed that he has been diagnosed with a skin cancer called a “melanoma”. The 57-year-old says that he was tested for the disease after his masseuse noticed a mark on his shin. So, what exactly is melanoma? Julia Newton-Bishop is a professor of dermatology at the University of Leeds…

Julia - Melanoma is a cancer of the cells in our skin that produce our skin colour. Most melanomas occur on some exposed skin.

Chris - And who tends to get them?

Julia - It occurs when genetic damage happens within the cell by exposure essentially to the sun. Within the sun's rays, there are shorter wavelengths called UVB, and these are important to us because they allow us to make vitamin D, but they also damage skin. And people who are vulnerable to melanoma have on the whole pale skin and they have the sort of skin that easily burns. So the people who are most at risk are those with the pale skin, often with red hair. And it's all about burning because it's during that process of sunburn that this genetic damage occurs, which later causes melanoma.

Chris - What about other sources of ultraviolet? People who go to tanning salons, for example.

Julia - It is well described now that excessive exposure to UVA in sun beds puts you at increased risk of melanoma. But I wouldn't want to give the impression that everyone's safe so long as they don't use a sunbed, because most melanoma occurs in people who get burnt in the garden on a lovely day like this, when they're outside. Especially if they're sunbathing.

Chris - Chris Evans is in his mid fifties. Is that the peak age or is he late to the party for melanoma?

Julia - 50 used to be about the average age for melanoma. It's a bit higher now, but it's not rare to see very young people in their twenties and thirties.

Chris - And what should a person look out for?

Julia - Half of melanomas occur in moles, as a changing mole. So I'm looking at my arms now, moles are usually quite circular. They grow to a certain diameter and then they stop growing - well-behaved moles. In a melanoma, you get a mole that's growing erratically and tends to be irregular in shape and irregular in colour, so a changing mole. Getting checked early is the important thing because if you have a melanoma on your skin and it's removed very early, then they don't come back. You've got it cured.

Chris - So if a person has something that they think might fulfil some of those criteria, how should it be investigated and what would be the likely outcome for the patient?

Julia - Clinical diagnosis gives you a very strong clue, and dermatologists are usually about 70 or 80% right. The norm is to then remove it surgically to cut the whole thing out with a narrow margin of normal skin at the edge, done with a local anaesthetic. And then that bit of skin goes off to the laboratory and the pathologist looks at that tissue under a microscope and looks for characteristic changes that tell us that this is a melanoma. Sometimes that's absolutely all that needs to be done. And for those in whom we feel we need to take a little bit more just to be sure, the patient would go back and have more skin removed from the edge just to be sure that we've removed all those cells. For many patients, a proportion of patients in whom the melanoma is a bit thicker, then they might consider having an optional operation on top of that, or the Sentinel Node Biopsy, which is a way of looking for cancer cells that have escaped the skin and are in the lymphatic drainage system. But essentially, the overwhelming majority of patients, 80%, are cured by that first surgery. And nothing more needs to be done.

Shipping containers stacked up

15:40 - Wind-power for supertankers and cargo ships

The idea is to re-purpose the design of aeroplane wings for ships to provide extra thrust...

Wind-power for supertankers and cargo ships
John Cooper, BAR Technologies

Much of the world’s heaviest cargo goes by sea. And the ships that move it burn what’s regarded as one of the nastiest fuels we have - heavy fuel oil: this is effectively “tar” left over from the distillation of crude. It’s so thick that the engines have to heat it up to keep it runny enough to use it. It’s also full of sulphur, and a big boat will burn off 100 tonnes of the stuff every day. Now, a vessel that used to run exclusively on that fuel has been retrofitted with a pair of giant vertical “wings” that use the power of the wind to knock a significant chunk off the fuel costs. John Cooper is the CEO of BAR Technologies, which designed the sails. I asked him to describe how these wind wings work…

John - I'm going to put you in an aircraft on the way to your holidays and I'm going to ask you to look out the window at the wing when you're taking off. That's the moment that the aircraft has the most vertical thrust. And what will be happening is you'll see the wing, but you'll see an element coming out the front of the wing and normally an element coming out the back of the wing. And then the wing is actually becoming more of a crescent shape. And then what we've done is we've taken that arrangement and made it vertical and put it on ships. And that means that that thrust is now horizontal, pushing the boat forward.

Chris - Seen from a distance, this is basically an oil tanker with a couple of big aeroplane wings sticking out of it. How much thrust will this actually generate for the boat?

John - So it will produce enough thrust for each wing to save one and a half tons of heavy fuel oil per day. So this is significant. So that first one that you see has two wings, so therefore it's three tons of heavy fuel oil per day. And even more importantly, for our next generations, the carbon footprint is reduced by nine tons of CO2 per day. So the UK person going about their normal business emits nine tons a year. And we are trying to save that every day on this vessel.

Chris - And these wings, are they literally aircraft wing sized, each one of them that you've put on the boat?

John - Well, arguably bigger. The wings that you see on this boat are 37 and a half metres tall in their flying shape and 20 metres wide. These are big wings.

Chris - When a person sails, say a yacht, they adjust the positional angle of the sails in order to get the best amount of force forward for the boat relevant to the wind direction. So are your sails adjustable in the same way?

John - Exactly. So actually those three elements that I was describing are all mounted such that the centre element can rotate 360 degrees to provide either a fail safe position so there's no lift, and that means they're all in a line pointing towards the wind or in a really strong thrusting flying shape where they're actually presented in the same way that an aircraft wing is on takeoff and in that nice crescent. It's part of our patented technology that we can present that wing in all different angles and create the required thrust from the prevailing wind.

Chris - Are these all retrofittable? So could we take some of those enormous great grain carriers you're seeing leaving Ukraine at the moment or trying to, some of the big oil tankers that are steaming around the world, can this be retrofitted to ships like that?

John - Absolutely. And indeed the first vessel sailed in as a motoring vessel called the Pyxis Ocean, and three weeks later sailed out as a hybrid vessel with two of our Wind Wings on board, and the same with the second vessel. So these legacy vessels we must concentrate on. We must retrofit wings to as many as possible. Of course, we're interested in new build designs as well. And we're working with many of the vessel designers around the world such that they incorporate our Wind Wings in their new build designs. But actually the problem's much bigger than that, and the legacy fleet is really important to us too.

Chris - And are they made of materials that are readily sourceable and have better carbon credentials than the fuel that they're saving? Because obviously it's laudable that you are saving that amount of carbon cost from burning fuel every day. But if arguably there's a huge great carbon cost to making these things, then it's a vanishing return. So what are they made of and how sustainable is that?

John - Yeah, so we've concentrated very hard on this aspect. We've purposely stayed away from carbon fibre. We've concentrated on materials that are already used in the industry, readily available in the locations that we are going to be making them. So our central mast is made of D32 and D36 steel, which is ship building steel. And the elements clad around that mast are made of glass composite, which is the exact same materials that the world is making wind farm blades from. So the technologies are known, the materials are known, we stayed away from materials that would be new and have a bigger footprint than those already used. And of course when we're talking about one and a half tons of fuel, that's 4.65 tons of CO2 per wing per day. The cost in terms of the environment of making the wings is totally minuscule in comparison to the savings made even over the first week.

Chris - And how big is the potential market if this takes off and you've got shipping magnates all over the world who are now coming to you saying, can we implement this design? Can we fit this? How big is that market?

John - Well, the good news is we have got shipping magnates all over the world coming to us to order wings. So they're all just waiting for the results of this first voyage, which I can absolutely tell your listeners are very good indeed, so there's an exclusive for you, Chris. I think that we'll be making 200 wings next year, 400 wings the year after, and we'll be going from there. So my biggest headache is finding places and supply chains to make lots of wings. Good problem to have.

Water vole

22:23 - Water vole reintroduction in the Lake District

They were almost wiped out by American mink, but now they're making a comeback...

Water vole reintroduction in the Lake District
Lee Schofield, Haweswater

To the Lake District now, and hundreds of water voles have been released at a secret location close to Haweswater. The move is part of an attempt to create a thriving population of the endangered species in Cumbria. Chris spoke with Lee Schofield, site manager for RSPB at Haweswater...

Lee - Water voles were previously a really abundant and very widespread species. Sadly, due to predation by invasive American mink, and also habitat loss, they've declined by something like 90%. We've been working really hard around Haweswater to restore the habitats, to restore a whole kind of mosaic of habitats actually, and also to control those mink in order to bring the water voles back again. And we know that they were there quite recently, there were old burrows there suggesting that they were probably around in the area a few decades ago - 40, 50 years ago. And they were a really important species in their own right, of course, but they're also a really vital part of the whole ecosystem. They're a big prey item, so they feed lots and lots of other species. So it is really important to bring them back for their own sake, but also for the health of the whole ecosystem.

Chris - Where do you get them from in the first place when you want to do a reintroduction programme like that? Do you breed them up artificially as it were, and then transport them? Or do you go to an area where they're in relative abundance and trap some and bring them? What's involved in moving and then reestablishing a species like this?

Lee - So these ones came from a specialist conservation breeder, a chap called Derek Gow, and he has built up locally specific, captive bred populations. So because we're in the North of England, these are a sort of Northern clade. So they were taken from a site that, as you say, had sufficiently healthy populations from which some could be taken. They've been bred up to build up the numbers and their numbers can be built up very quickly. Like all rodents, they reproduce very rapidly. So each female water vole can have between two and five litters a year, and each of those litters can have between two and eight young per litter. So when the conditions are right, their populations can build up very rapidly. So Derek Gow provided these animals to us and we released 204 of them into the site that we're looking after up at Haweswater, and then a further 161 were released just down the valley.

Chris - And what is the marker of success? How would you know if they're actually establishing and doing well?

Lee - So we can survey for them. They leave quite distinctive signs. They're quite secretive creatures. A good quality habitat for water voles is very complex with lots of places for the animals to hide away in. But they do leave very conspicuous droppings. They have droppings, which are described as being about tic-tac sized and shaped, so they're relatively easy to find and they also leave tracks and slides and tunnels, quite distinctive burrows that have one opening on the surface and one near the water's edge. We'll be able to confirm that they're still present and what we want is for their population to expand. So the two populations, they're on the same catchment. So over the course of the next few years, we're going to be working with Eden Rivers Trust and a range of other partners to try and fill in that gap, so we hope that they will expand naturally as we continue to control the predatory mink. But also we can supplement with additional releases to get a connected landscape scale population reestablished again.

Cat with yellow eyes looking at the camera

Can cats and dogs catch Covid?

Our very own Chris Smith took on the challenge...

So can cats and dogs, and other animals, catch covid? Or, more accurately, can they catch SARS-CoV-2, the coronavirus that causes Covid-19 disease in humans?

The answer is absolutely, yes. The Covid-19 coronavirus is actually not naturally an infection of humans: it's what's known as a "zoonosis" - an infection that has spread to us from animals.

And while the jury is still out on whether the virus escaped from a Chinese laboratory along the way, it nevertheless almost certainly began as an infection in a bat; we know this because the genetic codes of coronaviruses carried naturally by bats is remarkably similar to the genetic code of the Covid-19 SARS-CoV-2 virus.

Around the world billions of people have caught the infection, and many of them have exposed their pets, and their farm animals in the process.

There are reports of household cats and dogs, as well as mink, ferrets and polecats testing positive for the virus.

And in the Chinese city of Wuhan, where the pandemic began, 15% of the feral cats tested in the aftermath of the outbreak were positive for antibodies to the virus, proving they'd been exposed, possibly through scavenging through human waste.

These animals are susceptible to infection because they are mammals like we are, and share similar biochemistry making them targets.

But they also seem to fare better than humans, on average, when they catch the disease, so why is that?

The reason is that viruses evolve to become highly optimised to their natural hosts.

The best outcome for any virus is to be minimally disruptive for their host, while achieving maximum infectivity and therefore transmissibility.

Disable your host too significantly, or kill them even, and they won't go about their business infecting others quite so readily! You'll also eventually run out of victims to infect.

So in its bat host, the Covid-19 virus is relatively benign. But when it jumps the species barrier into us, the virus is ill-adapted to our physiology. The immune evasion that works well in a bat turns into a massive case of overkill in some people.

But in your dog or cat, on the other hand, the reverse is true: the virus struggles to gain much of a toehold; it cannot grow very efficiently and the infection tends to smoulder rather than turn into an inferno before the immune system smothers it.

And it's not just a one-way street. Some infections trivial for humans are lethal to wild animals. Two viruses that cause the common cold in us, called RSV and HMPV, can wipe out chimpanzees, killing up to one in five young animals for the same reason: that adaptations that make these viruses better bed fellows for us can render them lethal for even our close animal cousins.

So this is why biologists, conservationists and healthcare and animal practitioners talk about "one health": viruses can and do spread between species with highly unpredictable results; and that's why we need to try to keep tabs on them.


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