Forensic Ecogenomics

The Application of Microbial Ecology Analyses in Forensic Contexts

T. Komang Ralebitso-Senior

• Publisher: Academic Press
• Year: 2018
• Print ISBN: 9780128093603
• eBook ISBN: 9780128096093
• Topic: Law
• Subtopic: Forensic Science
• Index: Law

Forensic Ecogenomics: The Application of Microbial Ecology Analyses in Forensic Contexts provides intelligence on important topics, including environmental sample provenance, how to indicate the body decomposition timeline to support postmortem interval (PMI) and postmortem submersion interval (PMSI) estimates, and how to enhance identification of clandestine and transit grave locations. A diverse group of international experts have come together to present a clear perspective of forensic ecogenomics that encapsulates cutting-edge, topical and relevant cross-disciplinary approaches vital to the field.- Considers the effects of decomposition on bacterial, fungal and mesofaunal populations in pristine ecosystems- Examines the role of the microbiome, necrobiome and thanatomicrobiome in postmortem interval estimations- Focuses on the application of different analytical techniques across forensics to enhance/expand the crime scene investigation toolkit- Written by a wide range of international experts in their respective fields

Chapter 1

General Introduction

Method Applications at the Interface of Microbial Ecology and Forensic Investigation

T. Komang Ralebitso-Senior, and Ayodeji O. Olakanye Teesside University, Tees Valley, United Kingdom

Abstract

This introductory chapter sets the scene for “forensic ecogenomics” as a subdiscipline in forensic science, and links subsequent chapters' topics by identifying how each underpins and/or illustrates this cross-/multi-/transdisciplinary area of research. The narrative considers the effects of decomposition on bacterial and fungal populations in pristine ecosystems. The potential application of forensic ecogenomics in contaminated environments, among other contexts, is considered succinctly in the summary chapter. Although emerging forensic ecogenomic studies are focusing on the microbial communities of the decomposing body itself, research is also being implemented on the micro- and macrobial ecology of the surrounding terrestrial ecosystems in particular. Therefore considerations have been made on the role of the “epinecrobiome,” “necrobiome,” “thanatomicrobiome,” and soil microbiome in postmortem and postburial interval estimations. A central thrust is the application of different analytical techniques, which have been developed largely for microbial ecology, in forensics to enhance/expand the real crime scene investigative toolkit.

Keywords

Cross-disciplinary; Forensic ecogenomics; Macrobial ecology; Microbial community dynamics; Microbial ecology analyses; Necrobiome; Soil

The Context and Rationale

Microbial ecology, or “microbiome science and technology,” has a newfound role in forensic and crime scene science. Thus an inherently multidisciplinary topic where soil scientists, soil ecologists, microbiologists, molecular microbial ecologists (microbiome scientists), computer scientists, and environmental engineers have exchanged knowledge during the past few decades has a real opportunity to initiate a second molecular revolution in forensic analyses. This is evidenced by the emergence and use of several terms and disciplines that have explicit and/or inferred meanings. The applications of these novel disciplines can be specific, precise, or interchangeable, sometimes depending on who is using them and the context. It is essential therefore to provide the background and provenance for each of these terms and disciplines by reflecting on their origins as understood from published literature, what their original intended meanings were, and their uniqueness and/or overlaps. The discussion is presented within the context of the other established or well-recognized forensic subdisciplines. Also since most of the subsequent deliberations are underpinned by “forensic taphonomy” (e.g., Stokes et al., 2009), the discipline is discussed in a dedicated section herein and then in Chapters 2 and 3.

According to Coyle (2004), “forensic botany” “is a marriage of many disciplines ... [that includes] plant anatomy, plant growth and behavior, plant reproductive cycles and population dynamics, and plant classification schemes (morphological and genetic) for species identification.” Bock and Norris (1997) included plant ecology in this list within their historical overview that also reflected the application of the discipline in real criminal investigations. This particular reference justifies therefore the study of plant–microbe interactions within forensic contexts, which is yet to be explored. Parallel to molecular analyses in other forensic subdisciplines, Ferri et al. (2009) targeted two DNA regions, psbA-trnH and trnL-trnF, of the chloroplast to create a species identification system, which subsequently differentiated plants at family, genus, and species levels. Similarly, Ward et al. (2005) developed polymerase chain reaction assays for the mitochondrial genome and tested these successfully using 25 different species of grass. Uitdehaag et al. (2016) used trace soil samples for parallel terminal restriction fragment length polymorphism (T-RFLP) bacterial community profiling and palynology in a rape case.

As reflected by many researchers (Chen et al., 2009; Dekeisshieter et al., 2009; Donaldson and Lamont, 2013; Forbes, 2008; Forbes and Perrault, 2014; Kasper et al., 2012; Statheropoulos et al., 2005, 2007; Vass et al., 2004; Vass et al., 2008; Vass, 2012), “forensic chemistry,” the use of chemical science in forensic contexts, is probably one of the more established forensic subdisciplines for postmortem interval (PMI) estimation. It is underpinned typically by the use of spectroscopy, spectrometry, chromatography, magnetic resonance, and mass spectroscopy, among other techniques, to measure the concentrations of a range of decompositional and metabolic products including, but not limited to, volatile organic compounds, fatty acids, lipids, and proteins (see also Chapter 3, Table 3.1).

The biochemical products that are characteristic of specific decomposition stages are also responsible for attracting certain insect species to the decomposing carrion (Arnaldos et al., 2005; Carvalho et al., 2000; Dillon, 1995; LeBlanc and Logan, 2010; Ma et al., 2012; Paczkowski et al., 2012; Tomberlin and Benbow, 2015). This establishes a direct link to “forensic entomology” where the successional entomological clades that colonize the carrion/cadaver and contribute to its rate of decomposition have been used widely in aiding PMI calculations, including in real crime scenarios (see also Chapters 4 and 8). The colonization trends are determined further by environmental conditions and associated materials such as temperature, sunlight, and clothing (Denier, 1...

Table of contents

• Cover image
• Title page
• Table of Contents
• Copyright
• Dedication
• List of Contributors
• Preface
• Acknowledgments
• Chapter 1. General Introduction: Method Applications at the Interface of Microbial Ecology and Forensic Investigation
• Chapter 2. Forensic Taphonomy
• Chapter 3. The Method Debate: A State-of-the-Art Analysis of PMI Estimation Techniques
• Chapter 4. Implications of the Investigative Animal Model
• Chapter 5. The Role of the Microbiome in PMI Estimation
• Chapter 6. What Is the “Thanatomicrobiome” and What Is Its Relevance to Forensic Investigations?
• Chapter 7. Assessing Subsurface Decomposition and Potential Impacts on Forensic Investigations
• Chapter 8. From Experimental Work to Real Crime Scenes and the Courts
• Chapter 9. Summary: An Assessment of Achievements, Limitations, and Potential of Forensic Ecogenomics
• Index