True crime meets forensic science
Oct. 26, 2022

E16 Isotope Analysis | It’s in the Water

How minerals in water helped solve a heinous crime in Ireland

You know the phrase, you are what you eat? Well, it’s true. Isotopes from the water we drink and the water in the food we eat can tell scientists where we live, and where we have traveled and lived in the past. Isotope analysis is quickly becoming a forensic tool that when paired with DNA testing can help solve some of the oldest cold cases. We introduce you to an expert in the field who breaks it down for us and explains how it’s been used to help solve one of the most heinous crimes in Ireland. Full transcript available at  Learn more about your ad choices. Visit


Amanda: This podcast contains frank descriptions of human remains and physical violence. Listener discretion is advised. 

Amanda: In 2005, a bunch of kids in Harnett County North Carolina were skateboarding around a burned out, abandoned house during a day off from school...then, they spotted something. 

Ian Campbell: He was like, dude, I found a skeleton. 

Jacob Campbell: Kind of freaked me out, how often is it that you find a dead person around your house? 

Jacob Campbell: I thought it was like a fake skeleton that someone just threw up there, but then I got to looking at it and saw that it was actually a real skeleton and we went and got my mom. 

Sheri Campbell: And it looked very real, I did not think it was a prank. We don’t know of anybody that’s missing but I’m sure someone is looking for them, I mean that’s a person. 

Amanda: Investigators were all over the case in the beginning. But they had no leads and no local missing person cases to connect it to. Fifteen years later, a team of investigators planned a new approach: isotope analysis. 

In lay terms, isotopes are tiny particles that show up in the water we drink. Basically, they’re environmental markers that point to specific minerals being present in the soil and water where we live and travel. These markers show up in your teeth, your hair, your bones...  

In the case of this skeleton found in Harnett County, isotope analysis done in 2020 provided detailed information on the life path of the unidentified person. Including that he had been born in Texas, spent some time in the southeast, like Georgia and Florida, and more recently moved north, up to North Carolina. That information served as a kind of guide to let the investigators know if they were on the right track. And when the investigation into the man’s identity was complete, it turned out. His parents had met in Texas when his father was serving in the US Air Force. His parents got divorced and his father moved to North Carolina, while the boy stayed with his mother who was a schoolteacher. They moved around a lot; to Georgia and to Florida. And then he moved to North Carolina to his father’s home, just like the isotope analysis indicated. 

Amanda: In 2021, the team of forensic genealogists, scientists and investigators were able to make the announcement. I was there to cover the story for WRAL. 

WRAL archival tape (1/25/21) Amanda Lamb: The man has now been identified as 24-year-old Michael Baker; a drifter they think died when the abandoned house caught fire. 

Sherriff Wayne Coats: It’s not the ending we wanted but in the end it brings closure to a family. 

Amanda: His family was grateful for the answers although they wished the dots had been connected earlier. But there’s no doubt that isotope analysis helped lead them to Michael. 

In this episode, an isotope expert explains the science and shows us how it has huge implications for solving cold cases and more. 

Glen Jackson: You can take someone that's been dead for a thousand years and determine where they lived when they were nine years old. 

Amanda: And he tells us the story of how this kind of science helped solve a gruesome murder in Ireland, a murder that might never have been solved.   

From WRAL Studios, this is What Remains: stories of connecting unidentified human remains to the missing and the murdered. I’m Amanda Lamb. 

Amanda: In March of 2005, another group of boys playing on the other side of the Atlantic along the banks of the Royal Canal in the northern part of Dublin, Ireland, found a dismembered body. The man’s torso had been sliced in half. His head, arms, and legs had been cut off; his genitals removed. The pigment in the man’s skin had disintegrated over time. Upon first observation, he looked white.  

During an examination by a forensic anthropologist, un-exposed skin revealed that the man was actually Black. 

The man’s arms and legs were recovered. One of his legs was found floating near a park ten days after the boys’ initial discovery. It was still wearing a sock. His head was never found so they couldn’t use dental records. The DNA was not a match to anyone in the federal database, and as far as fingerprints go... 

The Irish police known as the Garda were able to get some prints from his hands, but they didn’t match anyone.  

Glen: So, there was really no identifying features by which to identify the victim.  

Amanda: That’s Glen Jackson, Forensic and Investigative Science professor at West Virginia University. He agreed to walk me through isotope analysis and how it works, and he told me about this amazing story. 

So, getting back to that investigators in Dublin decided to contact the Environmental Forensic and Human Health Laboratory at Queen’s University in Belfast to see if they could do any scientific testing that might yield clues to the man’s identity.  

Glen: So, they used isotope ratios. They looked at the hair and the bone in the individual and from the bone, they could tell that the person had probably spent the early parts of their life in like close to equatorial region, like the Horn of Africa, right? Like, Somalia, for example. 

Amanda: And the isotope testing from his hair revealed that he had been in Ireland at least 7 months. 

This was a breakthrough use of this kind of testing. Never before could scientists remember a time when isotopes had been used to try and help solve what was clearly a murder case. 

After the break, how isotope analysis can help solve these kinds of cases and what happened to that man found dismembered in Ireland. 

Glen: My name is Glen Jackson. I am the Ming Hsieh distinguished professor of forensic and investigative science at West Virginia University. 

Amanda: Glen lives up to the distinguished part of his title. He’s appeared in more than 80 publications, spoken at 120 plus conferences, and he’s helped secure more than 5 million dollars in state and federal funding for his research.  

He’s also the founder and co-editor of a journal called “Forensic Science.” He’s on prestigious boards and committees and his research even formed the story line for two episodes of the popular television show, Law and Order SVU... 

I reached out to him after I learned that he was a leader in the country in studying isotopes. 

Amanda: For most people who don't really understand the science or know much about it, including me. Tell us what isotopes are. Let's start right there. Let's just talk about what isotopes are. 

Glen: Sure, there are two types of isotopes, stable and unstable. So, the unstable ones are the ones that we probably are familiar of in terms of radioactivity. So, these are the ones that spontaneously decompose and release a lot of energy. We can harness that in nuclear power, or we can use it for destructive purposes, like bombs. 

That's not the kind that we study. So, we study stable isotopes. So, these were formed billions of years ago when all the atoms that make up earth and everything on it were formed. 

Amanda: Okay, still not a hundred percent clear on this one. Frankly, it’s hard for a person so well-versed in his field to explain it to a non-scientist like me. 

I know. I'm sorry. I'm trying to break it down.  

Glen: No, no, it's fine. It's great. I'm so used to talking to other chemists. So, I'm trying to get a much simpler term. 

Amanda: So, here’s the definition of an isotope from the Merriam Webster dictionary: “Any two or more species of atoms of a chemical element with the same atomic number and nearly identical chemical behavior but with differing atomic mass or mass number and different physical properties.”  

Here’s how Glen put it... 

Glen: So, for example, carbon. Carbon is called carbon because it has six protons. But some carbon has six neutrons in the nucleus and some carbon has seven neutrons in the nucleus. And the difference between them is, is only a difference in mass. The neutrons weigh well, of course, a very, very tiny amount. But using very sophisticated analytical instruments, we can measure the mass difference between a carbon that has seven neutrons and carbon that has six neutrons. And so, we can measure these isotope ratios for a wide variety of elements and determine something about the origin of those elements in things. 

Amanda: Glen explains isotopes are in our hair, our teeth and our bones.   

Glen: There's strong relationships between our diets and the isotopes in us. So, for example, just taking the case of carbon, most carbon starts life in the atmosphere as carbon dioxide, and then plants will take that carbon dioxide and through photosynthesis make like sugars and celluloses and things like that.  

And then when animals come along and eat that plant, they then kind of metabolize the, you know, the plant sugars, the cellulose and things like that. And they change the isotopes ratios a little bit. So, you know depending on the types of plants and the way they photosynthesis and then how far up the food chain you are the isotopes ratios in us can vary. And, and this is why from an atomic perspective, we very much are literally what we eat. 

Amanda: And even if your food isn’t coming from a farm down the street, you probably wash it or cook it in water – and just like we are what we eat, Glen says we are also what we drink. 

Glen: And it turns out that a lot of research has shown that most of the water that we consume really does come from the groundwater near us. Which, through a very long process comes from the surface water or the rainwater, that slowly kind of moves its way through the ground water table. So yes, we, we can pretty much tell where humans come from because of the hydrogen and the oxygen in them that comes from the groundwater, which ultimately comes from the rainwater near them. 

Amanda: This isotope science has huge implications for forensic cases. It can tell investigators where someone was born, where they lived, and where they traveled, or their immigration path. 

Let’s approach it the way a scientist would. The hair is the first place they look for isotopes. 

Glen: The hair is usually quite recent. And depending on the length of the hair, you'll store a chronological record of your diet and your geographic movements because of what you eat and drink. They will be deposited in your hair as it’s growing. 

Amanda: So, you can track where a person has been based on the longest part of their hair, and then track more recent movements as it gets closer to the scalp. Glen did a pretty interesting isotope study years ago illustrating how your hair can record where you’ve been and his test subject was pretty close to home. 

Glen: We did a study years ago where we collected my beard hair every Monday, Wednesday and Friday for about nine months. 

And, you know, the beauty of doing that is, and that was through like dry shaving basically, um, to the, to the skin. And so, by doing this every Monday, Wednesday, Friday, I could basically document my travel history. In a really tight window of hair growth. In that case, what it showed was, yes. When I traveled from Midwest, which is where I lived at the time to Utah to go to a conference that about 14 days after the visit, the isotope ratios in my hair jumped by about three units on the scale that we measure, which is, which is just astronomical in these, in these units. 

Amanda: But there are limits to what hair can tell you... 

Glen: So, for example, the hair only, only stores a chronological history, uh, in your case, I, I mean, I can see your hair is probably about 12 inches long. And so, you know that, so that's almost two years, right? So, we can go back two years, but we, from your hair, we can't tell where you were born, but if we could pull your teeth out, we could definitely say. 

Amanda: But joking aside, teeth can tell a lot longer history than hair. 

Glen : So, for example, when we're about eight or nine years old and we grow our incisors, like our canines, whatever we're eating and drinking when we're nine years old will be the atoms that stay in that tooth enamel for the rest of our lives. So, you can take a, you know a 90-year-old that still has their canines, right, and measure the tooth enamel, the isotope ratios and determine where they lived in the world when they were nine years old, those atoms do not exchange. They do not change their whole lives. 

Amanda: But in the case of that body discovered in Dublin, the teeth were never found yet there were plenty of other ways to use isotope analysis to solve the case. How it unfolded after the break. 

Glen: Basically, there was a dismembered human that was found on the banks of a canal. I think to try and hide the identity, the murderers had basically decapitated and severed the body into several pieces. 

Amanda: But when that body was found in Dublin in 2005, investigators were able to use the hair and bone to run an isotope analysis. And that analysis can be even stronger when tracing particular regions of the world. 

Glen: The uniqueness tends to be, for example, really hot places, like low altitude near the equator. You know, there's really distinct isotope profiles from the from people in those regions. 

Amanda: From the bone, they could tell the person likely spent the early parts of their life close to the Horn of Africa and from the hair that the person had most recently been living in Ireland and had been there at least 7 months. They later learned he had been in the country more than 6 years. With the help of this information, investigators were able to focus on a child they believed the man had fathered. They did a DNA test to prove he was the father, and in turn, that he had been the live-in boyfriend of the child’s mother, Kathleen Mulhall.  

Glen:  That investigative lead, the fact that he probably originated from the Horn of Africa and emigrated to Ireland was sufficient for the investigators to hone in on one suspect. You know, one particular person and they collected DNA from an immediate family member and proved that in fact, the person did originate from Somalia, and they had emigrated to Ireland seven years prior. 

Amanda: The victim was identified as 39-year-old Farah Swaleh Noor. He came to Ireland in 1998. He told the Irish government he was Somali and that he needed asylum from the civil war in his country. Investigators later discovered he was actually from neighboring Kenya, and told this story so he'd be allowed to stay in Ireland. 

Soon after this identification was made, in December of 2005, Kathleen Mulhall, who was in her late forties and her two adult daughters, Linda and Charlotte, were arrested in connection with Farah’s killing.  

The story prosecutors shared in court was that Charlotte who was in her early twenties and Linda, who was 30 at the time, spent the day partying with their mother, Kathleen, and her boyfriend, Farah, drinking vodka at pubs around Dublin and doing the drug ecstasy. At some point they all returned to Kathleen’s apartment, and according to investigators they were all pretty drunk when Farah who was sitting on the couch with Linda came on to her, started touching her in a sexual way and whispered “dirty” things in her ear.  

That’s when prosecutors say Charlotte attacked him with a small knife and slashed him across his throat. The court record indicates that Linda then repeatedly hit him with a hammer and Charlotte would go on to stab him 20 times. Investigators say the women then got to work cutting him into pieces in the bathroom, dividing his body parts into plastic bags and then making multiple trips to dispose of the evidence in the Royal Canal. 

The story about what happened to Farah’s head was never first, Linda told investigators she threw it in a trashcan at a park. Then other information surfaced that she may have carried the head on a bus in her son’s schoolbag and then buried it in a field. Either way, it was never found.  

After Linda confessed to the crime, Kathleen was released and fled the country for England. The sisters were dubbed in the media as “The Scissor Sisters” for the brutal way in which they cut up Farah’s body. 

The sisters were tried for murder in October 2006. Linda received life in prison and Charlotte was sentenced to 15 years behind bars. Their mother, Kathleen, returned from England to Ireland in 2008 to face charges that she helped cover up the murder. In May 2009, she was sentenced to five years in prison. 

Justice Paul Carney who presided over the sisters’ trial said during sentencing that it was "the most grotesque killing that has occurred in my professional lifetime." 

Amanda: The bottom line, Glen says, is that this situation showed scientists around the world how isotopes can really push a case forward when the victim is unidentifiedthat while DNA is still the gold standard for so much important information.... 

Glen: It can predict our genetic traits like hair color and eye color and things like that. But it can't tell you about geographical movements and that's something that isotope ratios can and do tell you.  

Amanda: Glen believes when it comes to isotopes, the sky is the limit. He and his colleagues have been exploring other things that isotope ratios might be used for. He’s done research on hair isotopes to create a profile of a person, which can be really helpful when you can’t get a solid DNA profile from a hair sample. With isotope analysis from hair, not only were they able to figure out where someone came from, but they determined the person’s sex with 94 percent accuracy. Their age group with 83 percent accuracy and were even able to isolate some medical conditions, like Type II diabetes. And while isotope analysis isn’t being widely used yet in forensic cases, Glen thinks it has huge potential. But even for’s never just about the science. It’s about using the science to create positive outcomes for humanity. 

Glen: You know, the most rewarding aspect of a research project is the, hope that it would actually be useful one day to solve a real crime. 

Amanda: So, if you’re a true crime junkie or science nerd like me this episode may have raised a few hairs on the back of your neck. I learned so much about isotopes. Including the disturbing fact that the phrase “you are what you eat” is not just an urban legend, but a scientific truth. 

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Today’s episode was researched, written and hosted by me, Amanda Lamb. It was produced and edited by Rachel McCarthy, with final mix by Doug Miller. Our Director of Podcast Operations is Anita Normanly and our Executive Producer is Ashley Talley.  

Thanks for listening.