Trace evidence: Locard’s exchange principle using invertebrates

   Department of Ecology and Evolutionary Biology

   Applications accepted all year round  Self-Funded PhD Students Only

About the Project

In most criminal or forensic investigations, much of the work focuses on the collection and assessment of biological traces of human origin. Invertebrates, particularly animal micro-parts (e.g., lepidopteran scales, insect exuviae, etc) and micro-invertebrates (e.g., tardigrades) are ubiquitous in the human environment. Samples lifted from a crime scene or from human clothes will very frequently contain micro-invertebrates.

For Dr. Edmund Locard, who described for the first time the relevance of trace evidence, every contact allows the transference of material, biological or not. Since his initial work in the early 1900s, when he described sampling methods, little advance has been achieved in relation to the lifting, assessment, and analysis of micro-invertebrate traces from crime scenes.

This project aims to further our knowledge on the importance of invertebrates in crime scenes and on how we can take more advantage of this information in forensic analysis. The student will gain expertise in modern techniques developed to sample and study invertebrates from a variety of environments resembling or associated with case work, and how this can be modified and adapted to crime investigations. Main objectives will include the development of new methods of collection, analysis and interpretation of invertebrates from different substrata, like soil, clothes, from simulated crime scenes, corpses and carcasses. Experiments on different sampling methods, the production of keys for classification of animal parts and micro-invertebrates, the exploration of reliable molecular markers and numerical analyses will provide training for a future trace evidence analysis expert.


Forensic Acarology Lab

The lab hosts a large collection of mite specimens (Acari) from crime scenes and from research on carcass decomposition; it is a fully equipped lab, with several microscopes dedicated to trace work, and a library. The PI, Dr Perotti is an expert in the topic, and conducts routine case work on traces together with Dr Medjedline Hani, a researcher associated with the lab.

School of Biological Sciences, University of Reading:

The University of Reading, located west of London, England, provides world-class research education programs. The University’s main Whiteknights Campus is set in 130 hectares of beautiful parkland, a 30-minute train ride to central London and 40 minutes from London Heathrow airport. 

Our School of Biological Sciences conducts high-impact research, tackling current global challenges faced by society and the planet. Our research ranges from understanding and improving human health and combating disease, through to understanding evolutionary processes and uncovering new ways to protect the natural world. In 2020, we moved into a stunning new ~£60 million Health & Life Sciences building. This state-of-the-art facility is purpose-built for science research and teaching. It houses the Cole Museum of Zoology, a café and social spaces.

In the School of Biological Sciences, you will be joining a vibrant community of ~180 PhD students representing ~40 nationalities. Our students publish in high-impact journals, present at international conferences, and organise a range of exciting outreach and public engagement activities.

During your PhD at the University of Reading, you will expand your research knowledge and skills, receiving supervision in one-to-one and small group sessions. You will have access to cutting-edge technology and learn the latest research techniques. We also provide dedicated training in important transferable skills that will support your career aspirations. If English is not your first language, the University's excellent International Study and Language Institute will help you develop your academic English skills.

The University of Reading is a welcoming community for people of all faiths and cultures. We are committed to a healthy work-life balance and will work to ensure that you are supported personally and academically.


Applicants should have a good degree (minimum of a UK Upper Second (2:1) undergraduate degree or equivalent) in Biology, Zoology or a strongly-related discipline. Applicants will also need to meet the University’s English Language requirements. We offer pre-sessional courses that can help with meeting these requirements.

How to apply:

Submit an application for a PhD in Biological

Sciences at


Further information:

Anthropology (2) Biological Sciences (4) Environmental Sciences (13) Forensic and Archaeological Sciences (16)

Funding Notes

We welcome applications from self-funded students worldwide for this project.
If you are applying to an international funding scheme, we encourage you to get in contact as we may be able to support you in your application.


Perotti, M.A. and H.R. Braig. 2020. Acarology in crimino-legal investigations: the human acarofauna during life and death. In Forensic Entomology: The utility of arthropods in legal investigations. Ed. by J. Tomberlin and J.H. Byrd. CRC. NY
Perotti M.A., H.R Braig and L.M. Goff. 2010. Phoretic mites and carcasses. In Current Concepts in Forensic Entomology: Novel Arthropods, Environments and Geographical Regions. Ed. by J. Amendt, C.P. Campobasso, M. Grassberger, and M.L. Goff. Springer, NY.
Frost, C., H. Braig, J. Amends and M.A. Perotti. 2010. Indoor arthropods of forensic importance. In Current Concepts in Forensic Entomology: Novel Arthropods, Environments and Geographical Regions. Ed. by J. Amendt, C.P. Campobasso, M. Grassberger, and M.L. Goff. Springer, NY.
Perotti, M.A., L.M. Goff, A.S. Baker, B.D. Turner and H.R. Braig. 2009. Forensic acarology. Experimental & Applied Acarology, 49:3-13.
Braig H.R and M.A. Perotti. 2009. Carcasses and mites. Experimental & Applied Acarology. 49:45-84.
Perotti M.A. and H.R. Braig. 2009. Phoretic mites associated with animal and human decomposition. Experimental & Applied Acarology. 49:85-124.
Please also view Dr Perotti’s profile:
Dr Alejandra Perotti – University of Reading

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