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.

 

Interview with Postgraduate Researcher Winsome Lee

winsome-lee

What is the focus of your research at the University of Leicester?

My research focus, namely for my dissertation is a comparative study of the forensic science progression in Hong Kong over a 40 years time frame. Hong Kong is where I have been brought up, and forensic science in the city is always covered with the mysterious veil. In 1965, we had our first forensic case. Till today, more than 40 years have passed by, it will be essential to evaluate how much we had progress.

Other than the dissertation research, since my focus is on forensic anthropology and forensic archaeology, I am also doing different excavation field schools, projects,  and osteology related research with other institutions.

Why is this research important to the field of forensic science and what do you hope to achieve by carrying out this research?

Technology and forensic techniques develop in a pace that we would never catch up with. However, due to constraints, not much comparative studies have been done, as an evaluation of the progress and development of the field, on the one hand. Sadly, funding is usually not entirely willing to sponsor studies of this sort, as they are hoping for new discovery most of the time, which likely lead to over generalization of ideas. Given the fact that forensics subjects heavily to experiences and contexts. Therefore, comparative study of forensic science is something that the profession needs yet tends to be overseen usually. On the other hand, a historical comparative study like the captioned one above, shows the same model over different time frames. It allows us to see the approach or policy from a macro level, namely environmental and political factors. In hope of this research, the government and the law enforcement will make improvements of their policies and models in order to facilitate the growth and application of forensic science in Hong Kong.

What does life as a postgraduate researcher entail?

Grad school life, as we all know, is tough. It is the kind of life that you have a full plate and always do not know where to start with. A lot of time management is involved, especially when I am also working alongside the study. People say you can use the senior year of undergraduate as a postgraduate tryout, I find this mostly correct! Also, other than studying, you are constantly looking for research and publication opportunities. Every time, when we are struggling, my pals and I keep asking ourselves, “why would we do this to ourselves.” But the sense of achievement is never better when you have accomplished something and survived a semester after another.

What are your plans for after you have completed your research?

After completing the existing project in the University of Leicester, I would be looking for PhD opportunities in either bioarchaeology, or biological anthropology.

Also, I have several real life forensic projects with police and other authorities ongoing and lined up. I am all excited and looking forward to all these amazing opportunities ahead!

Do you have any advice for students hoping to pursue a position in forensic research?

Keep your mind open!

First of all, forensic science itself is a relatively broad profession. Some of my friends switched from one discipline to another after trying out things, from forensic anthropology to law, from forensic pathology to forensic photography. You never know until you have tried. So first thing will be, to grasp as many opportunities as you can, then decide.

Once you made your choice, you also have to remember that forensic scientist is a relatively narrow yet competitive profession. What I mean is that, there is only certain demand in the authorities or law enforcement for forensic experts. If no one retires, you probably will not get a job. So it is always beneficial to have a broader, or second profession focus besides forensics.

Also, it is also very important to know that not every forensic scientist is good with doing research. Some are good with applying what we have learned, rather than doing research and making new discoveries. Be open minded, and do not get frustrated! Keep in mind that, either way we are making remarkable contribution.

Follow Winsome’s blog “Traces in Bones” here.

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.

Webpage

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

Also, you can follow #scentofdeath and #teamtaphonomy

Introducing the Controversial Psychoactive Substances Act

Introducing the Controversial Psychoactive Substances Act

As of this week the Psychoactive Substances Act came into effect in the UK, a long-awaited and much-disputed piece of legislation that will attempt to transform the existing drug marketplace. The act will make it an offence to supply any substance that can produce a psychoactive effect (of course with the exception of the likes of alcohol and caffeine), aiming to specifically target new psychoactive substances (NPS) or ‘legal highs’, which have thus far evaded the Misuse of Drugs Act.

But just what are New Psychoactive Substances, and why has it been so difficult to enforce laws against their supply and use?

spice

NPS are synthetic chemical substances created to mimic the effects of existing illegal substances, such as cannabis or ecstasy. These drugs are often designed in such a way that they are sufficiently chemically similar to an illicit drug to cause the desired psychoactive effects, but adequately different to bypass the existing legislation.  The legislation currently controlling illicit substances in the UK is specific in the substances under regulation, meaning any slight changes to the chemical structure of an illicit drug can technically render the drug uncontrolled and legal to supply or use.

New psychoactive substances are typically sold as powders, pills or smoking mixtures (somewhat resembling cannabis). You may have heard these drugs referred to as “legal highs”, rather inaccurately indicating they are legal and even safe to use. But a brief internet search will pull up an array of news pieces highlighting unexpected illnesses and deaths brought on by the use of these drugs. The primary danger surrounding the use of new psychoactive substances is the lack of research involving these substances, exacerbated by the ever-changing and difficult-to-monitor composition of the drugs. In addition to this, as NPS are specifically sold as being unsuitable for human consumption, thus avoiding certain regulations, the user cannot be confident in exactly what they are buying. Although many legal highs do offer a list of ingredients on the packaging, the highly unregulated nature of this market casts doubt on the accuracy of such information. Forensic analysis of NPSs has shown that they may contain unexpected constituents and even quantities of illicit drugs.

The NPS market has boomed in recent years, with new drugs hitting the streets faster than scientists can even identify them. They have thus far been widely available online and in head shops (establishments openly selling paraphernalia for the use of cannabis and other drugs), typically advertised as bath salts or plant food. Unfortunately the ever-changing variety of ‘legal highs’ available has presented forensic scientists with a particular challenge. The analysis of more typical drugs is relatively straightforward, with the analyst armed with well-trialled presumptive tests, analytical methods and libraries for comparison. However as new psychoactive substances are developed with modified chemical structures, they may not react with presumptive tests and library matching may prove useless without a comparison.

The premise of the act has come under great scrutiny, with opponents asserting the Act will blindly ban harmless substances (not true) or that it will be utterly unenforceable (somewhat true). A similar piece of legislation has been instigated in the Republic of Ireland, but with little success, as highlighted by the extremely low number of successful prosecutions under the law. In fact, the implementation of this legislation in Ireland was actually followed by an increase in NPS use amongst teenagers from 16% to 22%. That is not to say the legislation was the cause of this increase, but it is an interesting point nonetheless.

Despite the criticism and uncertainty, the Psychoactive Substances Act will attempt to curb the supply of psychoactive substances and protect potential users of these drugs. Although it will not be an offense to possess new psychoactive substances for personal use, it will be a criminal act to supply such substances. It will be inconceivable to halt the online sale of psychoactive substances, but it will be possible to prevent head shops, of which there are hundreds around the UK, from blatantly advertising and selling these drugs. Although the Psychoactive Substances Act promises to be a difficult piece of legislation to enforce, if at the very least it prevents new psychoactive substances from being freely advertised as a normal and ‘safe’ alternative to drugs, a great improvement will be made. But only time will tell if this new piece of legislation will really reduce the use of these no longer legal highs.

 

References

Home Office.Trade in so-called ‘legal highs’ now illegal. [online] Available: https://www.gov.uk/government/news/trade-in-so-called-legal-highs-now-illegal

New Psychoactive Substances Act 2016 [online] Available: http://www.legislation.gov.uk/ukpga/2016/2/contents/enacted