VX and Other Deadly Nerve Agents

It has now been confirmed that Kim Jong-nam, the half-brother of North Korean Leader Kim Jong-un, may have been assassinated using a highly toxic nerve agent known as VX. The attack occurred last week (13th February) in Kuala Lumpur airport, suspected to have been committed by two women who reportedly sprayed the chemical into his face before fleeing the scene.

VX, or S-[2-(Diisopropylamino)ethyl] methylphosphonothioate, is a nerve agent initially developed at the Porton Down Chemical Weapons Research Centre in Wiltshire, UK in 1952. Having originally been the focus of research elsewhere into the development of new organophosphate compounds as pesticides, the British military soon established an interest in the compound and continued its development.

vx-wiki

S-[2-(diisopropylamino)ethyl] methylphosphonothioate) or VX

Typically encountered in liquid form, this clear or sometimes amber-coloured, oily substance is notoriously difficult to detect, lacking in both taste and odour. Its toxicity makes it one of the deadliest chemical warfare agents, requiring as little as 10mg adsorbed through the skin to be fatal. Its deadliness is only further increased by the persistence of the agent, making it difficult to decontaminate people and areas tainted with the chemical.

Mechanism

The mechanism of action of VX is identical to many similar nerve agents. The compound can enter the body by a range of potential routes, including ingestion, inhalation or skin contact. Once inside the body, VX inhibits the function of acetylcholinesterase (AChE), an enzyme responsible for catalysing the breakdown of acetylcholine. Acetylcholine is released over a synapse following an electric nerve impulse, ultimately resulting in a muscle contraction. However when VX binds to the active site of acetylcholinesterase, it renders the enzyme inactive, thus preventing it from breaking down the acetylcholine. As the nervous system is flooded with excess acetylcholine,  repeated muscle contractions occur, eventually resulting in asphyxiation due to constant contraction of the diaphragm muscle.

The effects of VX will typically occur immediately after exposure, beginning with coughing, shortness of breath and a tightness in the chest. A headache and blurred vision soon follows, along with symptoms such as vomiting, diarrhoea and abdominal pains. Given a sufficient dose, seizures will then occur as the drug attacks the nervous system, eventually resulting in a coma and asphyxiation.

If administered promptly, there are antidotes for VX. Atropine, typically administered by injection, is an anti-nerve agent that blocks the acetylcholine receptors, alleviating the symptoms brought on by the nerve agent. However it is worth noting that compounds such as atropine are toxic in their own right and, although they may save the person’s life by alleviating the effects of the nerve agent, they will still have an adverse effect on the patient. In addition to this, pralidoxime (or 2-PAM), can be administered to reactivate the enzyme, thus reversing the effects of VX. 2-PAM is a safer compound to use than atropine, but its effects are much slower.

Other Nerve Agents

VX is just one of many known toxic nerve agents. Nerve agents can typically be classed as either G-series or V-series. G-series agents were first synthesised by German scientists during World War II, and include tabun (GA), sarin (GB), soman (GD), and cyclosarin (GF). The first compound to be discovered, tabun, was accidentally synthesised by Dr Gebhardt Schraeder, who was investigating the development of organophosphate-based pesticides. The German army soon realised the potential use of such compounds, and went on to fund the development of other nerve agents such as sarin. The G-series chemicals are all clear, colourless liquids at room temperature, but are largely utilised as gases due to their high volatility.

The V-series nerve agents, which include VX, VE, VG, VM and VR, were developed a few years later, initially in the UK but some later in Russia. Unlike the G-series compounds, V-agents are very persistent and are not easily washed away or degraded, meaning they can remain on surfaces for long periods of time.

Fortunately the V-series nerve agents have generally not been exploited outside of military research, and the death of Kim Jong-nam may well be the first known use of the toxic agent in an assassination. However the G-series have received a great deal of malicious use and attention over the years, ranging from the Tokyo sarin subway attack in 1995 to its recent use in the Syrian civil war

VX, along with numerous other toxic nerve agents, were banned under the Chemical Weapons Convention of 1993, rendering the manufacture, possession and use of such substances illegal.

 

References

BBC News. VX nerve agent: The chemical that may have killed Kim Jong-nam. [online] Available: http://www.bbc.co.uk/news/world-asia-39073558

University of Bristol Chemistry on the Screen. VX Nerve Gas. [online] Available: http://www.chm.bris.ac.uk/webprojects2006/Macgee/Web%20Project/nerve_gas.htm

 

 

 

 

 

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Interview with President of IsoForensics Inc., Lesley Chesson

southern-utahDifferent forms of elements–called isotopes–are found everywhere in the environment. These isotopes are incorporated into materials in varying ratios and the abundances of different isotopes thus serve as a record of the material’s formation. Analysis of a material for its distinct isotope signature can subsequently be used to reveal its history. Investigators have applied stable isotope analysis to a variety of materials of forensic interest including drugs, explosives, money, food, ivory, and human remains. For example, the isotopes in human hair protein can reveal the age of an individual, what s/he ate, and even how often (and where) s/he travelled.

What is your professional background and how did you come to be involved in IsoForensics?

I have a master’s degree in biology, with a lot of microbiology and chemistry experience. I entered the world of isotope forensics when I was hired to raise Bacillus subtilis (a cousin of the anthrax bacterium) under a variety of conditions – in liquid media, on agar plates, with different nutrients, etc. Because organisms record information about the environment in the isotopes of their tissues, the goal of this project was to develop models that allowed investigators to predict the growth conditions of a dangerous bacterium–such as anthrax–from its isotopic characteristics.

From its start in academia, IsoForensics developed into a private analytical services and research firm that explored novel forensic applications of isotope analysis. I enjoyed the challenges offered by that exploration. Since my first work on the B. subtilis project, I’ve been involved in other projects on human remains, foods and beverages, illicit drugs, and explosives.

Tell us about the work IsoForensics is involved in and what kind of clients do you typically work with?

Currently, IsoForensics provides a lot of human remains testing in unidentified decedent cases. The goal is to use the isotope records contained in hair, nails, bone, and teeth to reconstruct the travel history of individuals and provide new evidence on their origins: Were they local to the area of discovery? Had they traveled prior to death? Where might they have traveled? We work with a variety of law enforcement groups in this casework.

In addition to service work, we conduct basic and applied research through funded grants and contracts. One recent project has started to investigate the origins and ages of seized elephant ivory to understand the structure of illegal trade networks in Africa and Asia.

What are some of the most common sample types you are asked to analyse, and does anything pose a particular challenge?

In any given month, we can analyze a variety of materials – human and wildlife remains, illicit drugs, explosives, etc. One of the most challenging measurements we make is for strontium isotope ratios. There is so little strontium contained in organic materials that prep work takes place in clean lab settings. The preparation of materials for radiocarbon dating is also challenging since we must be extremely careful about contamination of “old” materials with “modern” carbon. However, these challenges are worthwhile since strontium isotopes can provide potentially useful geolocation data about materials while radiocarbon dating provides quantitative information on the “age” of materials.

Are there any areas of isotopic analysis that could benefit from further research and development?

Yes. Isotope forensics benefits from better and better models/methods for interpreting data. It’s one thing to compare isotope measurement results from sample to sample or from sample to a reference databank, but it’s another thing altogether to understand the process(es) driving isotopic variation in materials. For example, are the results we observe due to differences in TNT manufacturing process? Or coca plant physiology? Or elephant diet?

Isotope analytical techniques also change over time as better instrumentation is developed. Understanding the impact of different analysis techniques on measured isotope ratios is extremely important when comparisons are made – especially in legal settings. A major focus of the field is the standardization of practices and protocols, to generate comparable results over time and space (e.g., from lab to lab).

How has the need for isotope analysis in forensic investigations changed over the years, if at all?

The forensic application of isotope analysis has been increasing the past 10-20 years. This is partly due to changes in analytical techniques, which have made isotope ratio measurements faster and cheaper. In addition, those who could benefit most from forensic isotope data–law enforcement, regulators, etc.–have become more aware of the technique and it potential usefulness in various types of investigations. We as forensic scientists and isotope analysts can do even more to spread awareness about the technique and its many applications.

Finally, do you have any advice for students hoping to pursue a career in this field of work?

Isotope analysis is one (extremely useful!) tool in a forensic scientist’s toolbox. Having a background and training in other areas–such as anthropology, analytical chemistry, biology, biochemistry, geology, law, or statistics–can be very important when applying isotope analysis techniques and interpreting the resultant data. The field of isotope forensics is relatively small compared to some other forensic disciplines, so be sure to read papers, attend meetings, and network with scientists working in the field.

Visit the Isoforensics Inc. website for more information.

Sex Determination with Raman Spectroscopy

Sex Determination with Raman Spectroscopy

The ability to quickly identify a victim or suspect during a criminal investigation is crucial, and the use of fingerprinting and DNA profiling often proves invaluable in this. However, a fingerprint or DNA profile can only be associated with an individual if there is an alternative profile or database match for comparison.

But what can investigators do when comparison profiles are not available, rendering biological fluids found at crime scenes somewhat useless?

The capability of instantly establishing alternative information relating to a suspect – such as sex, age or a phenotypic characteristic – based on the analysis of the evidence could be a substantial benefit to an investigation.

In recent years, the use of both well-established and novel analytical techniques to ascertain information relating to a suspect or victim from bodily fluids has been the focus of a great deal of research. With an increasing number of analytical instruments becoming field portable, the possibility of in situ analysis at crime scenes and instant suspect information is quickly becoming a reality.

Raman Spectroscopy and Sex Determination

Most recently, researchers at the University of Albany (Muro et al, 2016) have highlighted the possibility of using portable Raman Spectroscopy to determine the sex of an individual based only on their saliva in real-time.

The study utilised a total of 48 saliva samples from both male and female donors of multiple ethnicities, depositing the samples onto aluminium foil and drying overnight. Samples were then subjected to Raman analysis and the chemical signatures scrutinised to determine whether or not the saliva of male donors differed from that of female donors.

Raman Spectroscopy is a non-destructive analytical technique used for analyte identification based on molecular vibrations. As a basic explanation, monochromatic light is initially directed towards the sample, some of this light simply passing through the sample and some of it being scattered. A small amount of this scattered light experiences an energy shift due to interactions between the sample and the incident light. These energy shifts are detected and transformed into a visual representation. The resulting Raman spectrum typically plots frequency vs intensity of the energy shifted light. The positions of different bands on this spectrum relate to the molecular vibrations within the sample which, if interpreted correctly, can allow for the identification of analytes.

Raman spectra are somewhat characteristic of the chemical composition of the sample. In the case of the saliva analysed in this study, the features of the spectra were largely caused by amino acids and proteins. When comparing the respective spectra from male and female donors, by eye they appear remarkably similar. However using multivariate data analysis, a statistical technique used to analyse data with multiple variables, the researchers were able to distinguish between the saliva of male donors and that of female donors, reporting the ability to ascertain the sex of the donor with an accuracy of an impressive 94%.

malefemaleramanspectra

Comparison of male and female saliva Raman spectra (Muro et al, 2016)

Although only a proof-of-concept paper, the research demonstrates the possibility of using portable Raman spectroscopy as a method of elucidating donor information, in this case sex, through the analysis of a bodily fluid. The researchers suggest further work will be conducted to include other bodily fluids and donor characteristics.

At this point, the usefulness of the research is limited. Although instantly establishing the sex of the donor of a bodily fluid can aid investigators in developing a suspect or victim profile more efficiently, the pool of potential donors is still huge. The total of 48 saliva donors used in this study is of course not a sufficient representation of the population, thus a much larger sample set would be required to fully evaluate the technique, including non-laboratory setting experiments. Furthermore, there is a wide range of medical conditions and additional factors that can result in changes in the chemical composition of saliva and thus could influence the effectiveness of this technique. Whether or not certain diseases or external influences can hinder gender determination using this method would need to be investigated.

Previous Research

The idea of utilising analytical chemistry to ascertain donor information is not in itself novel, and other researchers have attempted to achieve the same goal through different means.

In 2015, scientists also based at the University of Albany (Huynh et al, 2015) developed a biocatalytic assay approach to the analysis of amino acids in fingerprints to determine the sex of the donor. The study boasted an accuracy of 99%, with the sex differences believed to be due to the higher concentration of amino acids in fingerprints deposited by females.

Research by Takeda et al in 2009 used Nuclear Magnetic Resonance (NMR) Spectroscopy to determine differences between the urine and saliva samples of different donors based on the detection and comparison of different metabolites. Certain compounds, including acetate, formate, glycine and pyruvate, were found in higher concentrations in male samples, allowing for the differentiation between male and female bodily fluids.

The focus of such research is not limited to sex differentiation, for instance some research has even focused on establishing whether a blood sample belongs to a smoker or non-smoker. Utilising gas chromatography mass spectrometry with a solid phase microextraction pre-concentration step, Mochalski et al (2013) were able to effectively distinguish between the blood and breath of smokers and non-smokers due to the ten-fold increase in levels of benzene and toluene, a conclusion which has been repeated by other researchers.

Looking at just this small handful of studies, it becomes evident that certain analytical techniques have the potential power to ascertain a range of information about the donor of a bodily fluid. However all of these immunoassay and mass spectrometry techniques are typically time-consuming, requiring the transportation of a sample to a laboratory, sometimes extensive sample preparation, followed by a form of analysis that will often destroy the sample. This is evidentially not ideal during a time-sensitive criminal investigation in which sample amount may be limited.

To an extent, the research utilising Raman spectroscopy to determine sex from saliva does alleviate some of these problems. The portability of Raman devices allows for in situ analysis, removing the need for expensive and time-consuming laboratory analysis. As Raman spectroscopy is based on the interaction between the sample analyte and light, it is a non-destructive technique, allowing the sample to be preserved for storage and further analyses is required.

Although these techniques do not hold the power of DNA in almost irrefutably identifying the suspect, they may at least aid investigators in narrowing down their pool of suspects and steering the investigation in the right direction. No doubt further advances in analytical chemistry will allow for more accurate and robust techniques in the future.

 

References

Huynh, C et al. Forensic identification of gender from fingerprints. Anal. Chem. 87(2015), pp11531-11536.

Mochalski, P et al. Blood and breath levels of selected volatile organic compounds in healthy volunteers. Analyst. 7(2013), pp2134-2145.

Muro, C. L et al. Sex determination based on Raman Spectroscopy of saliva traces for forensic purposes. Anal. Chem. 88(2016), pp12489-12493.

Takeda, I et al. Understanding the human salivary metabolome. NMR Biomed. 22(2009), pp577-584.

 

Forensic Failures: Ray Krone & Bite Mark Blunders

Forensic Failures: Ray Krone & Bite Mark Blunders

In 2002, Ray Krone became the 100th wrongfully imprisoned person to be exonerated by DNA analysis in the US, but only after spending ten years of his life detained in Arizona prisons, including a number of years on death row.

On the morning of 29th December 1991, the owner of the CBS Lounge in Phoenix, Arizona went to his bar to discover the door unlocked, the lights on, and the naked body of 36-year-old Kim Ancona on the floor of the men’s bathroom. The victim, who had worked in the bar as a waitress, had been brutally stabbed to death.

The subsequent examination of the scene was somewhat fruitless and, although saliva was recovered from Kim’s body, little other physical evidence could be found. The only piece of evidence investigators had to work with was a series of bite marks found on the victim’s breast and neck. As the investigation continued, police began interviewing those close to the victim in attempts to shed light on the events leading up to her death. It transpired that the victim had told a friend that Ray Krone, a regular customer at the bar, was to help her close up the bar the previous night. Investigators jumped at the possibility of a potential suspect.

During an interview with Krone, a detective noticed that he had a very distinctive deformity of his front teeth, no doubt causing a unique bite mark. This characteristic would later lead to the nickname of ‘the Snaggletooth Killer’. Krone was happy to oblige when asked to provide a Styrofoam impression of his teeth for comparison purposes.

However unfortunately for him, a forensic odontologist soon declared that the Styrofoam impression matched the bite marks found on the victim’s body.

Krone maintained his innocence, insisting that he was at home in bed at the time of the murder, a story corroborated by his roommate. Despite this, Ray Krone was arrested and charged with kidnapping, sexual assault and murder.

As the trial commenced, it was clear there was little evidence for the prosecution to present, so they focused their efforts on the bite mark comparison. They hired forensic odontologist Raymond Rawson to conduct the comparison between the bite marks on the victim’s body and the impression of Krone’s teeth. Using compelling video footage attempting to show the physical match between the two, Rawson informed the jury that the match was “100 per cent”, and that only Krone could have made those bite marks. The defence chose not to call upon their own court-appointed forensic odontologist.

Despite a lack of DNA analysis or eyewitness testimony linking Krone to the crime, and the bite mark comparison being the only physical evidence implicating him, Ray Krone was found guilty and sentenced to death.

Three years later Krone was awarded a re-trial due to the prosecution team concealing the persuasive video tape concerning the bite mark evidence until a day before the original trial, but once again he was found guilty. Despite the opportunity to rectify the conviction being wasted, trial judge James McDougall aired his uncertainty: “the court is left with a residual or lingering doubt about the clear identity of the killer. This is one of those cases that will haunt me for the rest of my life, wondering whether I have done the right thing”.

Forensic Odontology & Bite Mark Comparison

As DNA analysis was not carried out during this investigation, Krone’s conviction was almost entirely based on the ‘expert’ opinion that his teeth matched the bite marks on the victim’s body.

Dental identification is based on the theory that every individual’s dentition is unique, and thus bite marks made by a person will be distinguishable. In theory, this is true – we all have different combinations of jaw sizes, varying dental work and unique wear patterns to our teeth. Bite mark comparison may involve a variety of methods, including overlaying appropriately-sized photographs of teeth and bite marks and fitting together physical moulds.

At the time, there was little reason to doubt the testimony of the forensic odontologist hired by the prosecution. Raymond Rawson was a well-established expert who was certified by the American Board of Forensic Odontology, his findings in this case were supported by another expert, and the discipline of bite mark comparison had been practiced for almost 20 years. Furthermore, a 1984 study had provided “statistical evidence for the individuality of human dentition”. The expert witness testimony seemed perfectly reputable.

Well, that is until we look a little closer.

The seemingly convincing 1984 study was actually research conducted by Rawson himself, and has since been widely criticised as being a flawed study, largely because he used hand-traced dental impressions for his comparisons, a non-randomised subject selection process, and statistical tests not relevant to his type of data. Other experts had quite rightfully stated that the results of the study should absolutely not be used in a legal case.

A study conducted ten years previously comparing bite marks in wax and pig skin to the teeth of subjects stated that, although bite marks in wax were easily assessed, those made in pig skin were difficult to examine and the results unreliable. The research concluded that incorrect identification of bite marks on pig skin were made 24% of the time under laboratory conditions, and even as high as 91% of the time when based on photographs taken 24 hours after the bite marks were initially made. The study highlights the clear difficulties in subjective fields of work such as forensic odontology. Experts will often be required to examine bite marks that are hours or even days old, obscured by bruising and abrasions and typically not entirely representative of the biter’s teeth. At times it is challenging enough to merely identify an injury as a bite mark, let alone successfully compare it to a set of teeth.

Despite these apparent shortcomings, Ray Krone was to spend a decade of his life behind bars.

Exoneration

Fortunately for Krone, he had an undeterred family behind him maintaining his innocence and the means of hiring proficient legal help and in 2002, with the help of attorney Alan Simpson, he successfully appealed.

DNA analysis had become, by this point in time, a well-established technique frequently utilised in criminal investigations. Analysis of bodily fluids recovered from the crime scene a decade earlier soon proved not only Krone’s innocence, but also the identity of Kim Ancona’s real killer. Kenneth Phillips, a man with a long history of repeated violent sex offenses, was serving time in prison for the sexual assault of a 7-year-old girl, but at the time of Kim’s murder was living a mere 600 yards from the scene of the crime. Despite his close proximity to the bar, his deviant history and the fact that he was at the time of the murder on probation for the assault of a neighbouring woman, Phillips was never considered a suspect.

On 8th April 2002, Ray Krone left prison a free man, the 100th person to be exonerated by DNA evidence. He would certainly not be the last.

Krone now lives in Tennessee, where he has since dedicated his time to criminal justice reform and the campaign for the abolition of the death penalty.

“I would not trust the state to execute a person for committing a crime against another person. I know how the system works” – Ray Krone.

 

References

Innocence Project. Ray Krone. [online] Available: http://www.innocenceproject.org/cases/ray-krone

New Scientist. Bite-mark evidence can leave false impression. [online] Available: https://www.newscientist.com/article/dn4758-bite-mark-evidence-can-leave-false-impression

Rawson, R. D. et al. Statistical evidence for the individuality of the human dentision. J For Sci. 29(1984), pp245-253.

State v. Krone, 897 P.2d 621, 182 Ariz. 319 (Ariz. 06/22/1995)

Whittaker, D. Dome laboratory studies on the accuracy of bitemark identification. Int Dent J. 25(1975) pp. 166-171.

Cover Image – https://www.flickr.com/photos/girlstyle/449883708/in/photostream

 

Fragrance Forensics: Using Perfume to Catch the Culprit

Fragrance Forensics: Using Perfume to Catch the Culprit

 

Every day we apply chemicals to our bodies in the form of perfumes, colognes, deodorants and moisturisers, producing a concoction of pleasant scents that can be quite unique. It is well-known that perfumes and other fragrances can be potent and persistent, lingering on clothes and skin for hours if not days. Furthermore, these aromatic mixtures lend themselves to being easily transferred from one person to another through physical contact.

As the field of forensic science advances, investigators are looking for different ways in which they can identify suspects and connect individuals, and perfume may be an ideal target. What if the fragrance worn by an individual could be identified on a chemical level and used to link that person to a particular person or place? Simona Gherghel and fellow researchers at University College London have aimed to achieve this using analytical chemistry techniques.

LLstructures

Linalool (left) and limonene (right), common components in perfumes and colognes.

Different perfumes and colognes are composed of a variety of volatile organic compounds (VOCs), which provide the products with their powerful and characteristic scents. Compounds commonly detected in such products include linalool, limonene, coumarin, geraniol and eugenol, often in varying quantities and mixed with an assortment of other components. Once applied, these fragrances are absorbed by clothing and skin and can be readily transferred to fabrics and other surfaces.

Using gas chromatography-mass spectrometry (GC-MS), a well-established analytical technique frequently utilised in forensic enquiries, the team analysed fragrances in a number of scenarios to investigate the extent to which chemical components could be transferred between surfaces and what circumstances might affect this transfer.

The research focused on a number of factors relevant to the use of fragrances as a potential form of trace evidence in forensic enquiries, specifically the method of transfer and the time between application of the fragrance and contact with another surface. Experiments involved contact between swatches of fragranced and fragrance-free fabrics, examining transfer of compounds when the fabrics were in contact with no friction, and forcefully rubbed together over periods of time ranging from 1 minute to 60 minutes. After controlled contact, swabs were collected from the fabrics and subjected to GC-MS analysis. Unsurprisingly, extended contact time led to an increase in transferred components. This may have the potential to indicate how long a victim and offender were in physical contact, whether it be fleetingly or for a prolonged period of time, the latter being more likely in the case of an assault.

This research also investigated the effects of time passed between application of a fragrance product and contact between two surfaces on the transfer and persistence of VOCs. Contact between a fragranced piece of fabric and a fragrance-free swatch was investigated at a number of time points ranging from contact occurring 5 minutes after fragrance use and to 7 days after use. As was expected, the number of chemical compounds transferred between the fabric swatches decreased with time, with larger-sized, less volatile molecules persisting for longer. When only 5 minutes had passed before contact occurred, an average of 24 volatile components were transferred from the perfumed fabric. However after 6 hours only 12 components were detected, and this decreased to only 6 components after 7 days. Although this shows that certain transferred chemical compounds can persist for days, there is a discernible decrease in their presence which ultimately makes the sample less detectable and less unique, as a smaller mixture of chemicals are available for identification and comparison.

Although this is the first published work demonstrating the transfer of fragrance between garments in a forensic setting, the possibility of identifying perfumes based on their chemical composition for forensic purposes has been previously examined by experts at Staffordshire University in the UK. Led by PhD student Alison Davidson, the team has been compiling chemical profiles of popular perfumes and colognes with the hope of distinguishing between brands of difference fragrances and ultimately using this information to aid criminal investigations.

The ability to identify perfumes and establish physical contact between two individuals based on VOCs could be of particular use in the investigation of sexual assaults and other violent crimes in which the victim and offender were in close contact. For instance, the contact between a victim’s perfumed clothing and the clothing of the offender could cause the transfer of volatile organic compounds to the offender’s clothing (or vice versa). Later analysis of a suspect’s clothing may then result in the identification of chemical compounds originating from the victim’s perfume, indicating physical contact and thus potentially supporting an accusation.

Although the research conducted has supported the possibility of utilising transferred VOCs in perfume and possible affecting factors to aid legal investigations, it is vital to consider that a greater range of variables must be taken into account if such analyses were to be utilised in real life scenarios. The degree of activity by the victim and offender and the time passed between the offense and forensic analysis must be considered, as should how unique the mixture of chemical components detected really is. Furthermore, if the transfer of perfume between fabrics can occur so easily, there is a distinct possibility that such a transfer could occur in entirely innocent circumstances, highlighting the importance of such analysis only being utilised alongside alternative sources of evidence.

The concept of studying the chemical composition of perfumes and fragrances to aid legal investigations is very much in its infancy, but with further research this technique may have the potential to offer investigators an additional tool to sniff out suspects.

 

References

S. Gherghel, et al., Analysis of transferred fragrance and its forensic implications, Sci. Justice (2016), http://dx.doi.org/ 10.1016/j.scijus.2016.08.004

 

Interview with Biological & Forensic Anthropologist Dr Geraldine Fahy

Geraldine Fahy

What is your current job role and what does this involve?

I am a lecturer in Biological/Forensic Anthropology in the Skeletal Biology Research Centre, University of Kent. During term-time I teach all aspects of Human Evolution from early fossil hominins, hunter-gatherer societies, to methodologies used to reconstruct the last common ancestor (LCA). I also convene a forensic anthropology module where I teach forensic taphonomy, excavation and recovery, disaster victim identification and biometric identification. We are in the process of developing our MSc Forensic Osteology and Field Recovery Methods which will run from Sept. 2017 which is very exciting!

What initially attracted you to this field of work?

I wanted to become a forensic anthropologist from the first time I read Kathy Reich’s debut novel, Deja Dead. Of course, fiction is fiction however by the time I started researching the topic and where I could study forensics, I loved the topic for itself, for the science and so continued. I have turned more towards analytical chemistry techniques and human evolution in recent years; however, my interest in forensics continues, and my education and employment background remains relevant, as most forensic science disciplines, including forensic anthropology, have solid foundations in science, with the ‘forensic’ aspect being related to chain-of-custody maintenance and courtroom presentation.

Can you tell us about the research you are currently involved in at the University of Kent?

I conduct research into dietary ecology and subsistence patterns of past populations using stable isotope analysis. I have previously conducted such research on a population of wild Western chimpanzees, as correlates for the LCA; however, my current research focuses on medieval dietary reconstruction from East and West Europe. I am also currently involved in a project looking at the effects of bone turnover rates on stable isotope values and am currently investigating potential stable isotope methodologies that may have future use in forensic identification.

Has your work led you to be involved in any legal investigations? If so, what did this involve?

I worked as a forensic anthropology intern at the Netherlands Forensic Institute where I looked at decomposition of muscle tissue following submersion in water for my MSc thesis. Following this I worked as a forensic anthropology intern for the UN Mission in Kosovo in 2007 where I assisted in the identification and repatriation of victims of the Yugoslavian conflict. Subsequently I worked as an Associate Forensic Expert for the UN International Independent Investigation Commission in Lebanon which involved evidence collection and cataloging in the investigation of the assassination of former Lebanese Prime Minister Rafik Hariri and others.

Do you have any words of advice for students wishing to pursue a career in forensic anthropology?

Do your research but don’t be disheartened if you end up doing a different degree initially; as long as it’s not totally removed (e.g. doing a business degree when you then want to work in science) it is possible to get where you want to go without a straight path. I would advise doing as many unpaid internships as possible, this is where you gain valuable experience and make contacts for the future. Importantly realise that what you want can change as the years go by and this is fine….you may start out wanting to work constantly in the field, but then realise this is not viable for you and end up in a lab or a classroom, just go with whatever feels right for you.

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Interview with Forensic Anthropologist Dr Anna Williams

hud pic

What is your current job role and what does this involve?

I am Principal Enterprise Fellow (equivalent to Reader or Associate Professor) in Forensic Anthropology at the University of Huddersfield. My time is divided between teaching undergraduate and postgraduate students, supervising MSc and PhD students, and doing research and forensic casework. I teach on the BSc/MSci Forensic and Analytical Sciences, and the MSc in Forensic Anthropology and the MSc in Risk, Disaster and Environmental Management. Part of my role is also to engage with the public and communicate our research to lay people, including school children, interested adults and other scientists. I regularly present at academic conferences, local interest groups, Science Festivals and public events. This year, I am presenting at the Royal Society Summer Science Exhibition. I have also been featured in several TV science documentaries, and regularly consult for TV shows like Bones, Rosewood and Silent Witness. I also write a blog about my adventures in forensic anthropology.

What initially attracted you to this field of work?

I did a mixture of sciences and humanities at A Level and could never decide which I liked best, so I chose Archaeology and Anthropology as my first degree. There, I was fascinated by what you could tell about individuals by their skeletal remains, for example about hominid evolution. Then I discovered the burgeoning science of Forensic Anthropology, on a short course at Bradford University, and that was it, I was hooked! I love how you can glean all sorts of information from the smallest pieces of evidence. I have always loved logic problems, and forensic anthropology offers the most exciting puzzles. The fact that it is often confronting, challenging and disturbing, and could help to bring criminals to justice, just serves to add to its appeal for me.

Can you tell us about the research you are currently involved in at the University of Huddersfield?

I specialise in decomposition and taphonomy (the study of how bodies decay in different environments). To do this, I use an outdoor decomposition laboratory. I lead a research group currently doing research into the gases given off by decomposing cadavers (we use pigs that have died of natural causes), and comparing that to the efficiency of police dogs that are specially trained to find dead bodies. We’re also looking at how skin colour changes in surface or water environments, and trying to find ways to improve our estimation of post-mortem interval and post-mortem submersion interval. Other research is focussed on the taphonomic changes that occur to bone and teeth in hot, arid environments. I am also running a citizen science project in order to improve age estimation of unknown individuals from dental eruption. There is a webpage and online questionnaire for anyone who would like to help us build a large, modern set of tooth eruption data to see if dental eruption ages are changing.

Aside from research, are you often involved in police casework, and what does this typically involve?

Sometimes I am asked by the police to attend crime scenes or mortuaries to undertake forensic examination of decomposed or skeletonised remains. They can be either the victims of crime, or the remains of people who have gone missing. I will determine whether they are human or animal, and if they are human, I will estimate the age at death, sex, stature and ancestry of the individual(s), and try to say something about their lifestyle, disease, injury and how they died. I work in conjunction with forensic archaeologists and odontologists, as well as pathologists, to reach an identification. I also do consultancy for forensic science providers and, on occasion, a mass disaster company that helps to ‘clean up’ after disaster and repatriate the victims. I am involved in disaster victim identification and the Emergency Operations Centre.

The existence of so-called ‘body farms’ has sparked great interest in the media. Are there plans to establish such a facility in the UK? What are the primary challenges associated with this?

I believe that Human Taphonomy Facilities, or ‘Body Farms’ as they have become colloquially known, are vital for the advancement of forensic science. We owe all that we know already about human decomposition to the Forensic Anthropology Center at the University of Tennessee, and there is so much more to learn. We need to know how human conditions like diabetes, cancer, smoking and drug use affect our decomposition, which is something we cannot learn from experimenting with dead pigs. Unfortunately, a lot of the data generated by the ‘Body Farms’ in the USA and Australia are not directly relevant to forensic cases in the UK or Europe, because of the different climate, insects and scavengers. The UK is falling behind the USA and Australia by not having one of these outdoor laboratories where vital decomposition research can be done on donated cadavers. There was an attempt to establish a Body Farm in the UK in 2011, but this failed for a variety of financial and political reasons. I think the main obstacles to getting one set up in the UK are lack of funding, public awareness and rivalry between academic institutions. I hope that, in the near future, we will be able to create a facility where researchers, academics and practitioners will be able to work together to improve methods of search and recovery, post-mortem interval estimation and identification of human remains.

Do you have any words of advice for students wishing to pursue a career in forensic anthropology?

Forensic anthropology is a very competitive field, and there aren’t many jobs out there, so you need to be dedicated and determined. It can also be hard work and distressing, so decide carefully whether you want to pursue a career in it. The best way to make yourself stand out from the crowd of other applicants to jobs is to have experience, so try to get as much hands-on experience as you can. This doesn’t have to be forensic (although, of course, that would be preferable), but can be in archaeological units or museums or hospitals (or even zoos), somewhere where you can deal with human (or animal) bodies.

Images from Research

These pictures show the progression of decomposition in a small (10kg) pig. The first picture shows the pig in the fresh stage, when post-mortem interval was less than 24 hours. The second picture shows the pig in the active decay stage, 25 days later. The brown froth is decomposition fluid that has been agitated by the movement of maggots. The body was bloated with decomposition gases, but has now collapsed, and the intestines are escaping. The skin has desiccated, but the hair is still intact. The skin has darkened and become leathery in texture. The bones are becoming detached from the body.

pig1

Surface pig 1, day 0

pig2

Surface pig 1, day 25

 

Website: www.forensicanna.com

Twitter: @Bonegella

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