A controlled method for the identification of forensic traces from clandestine grave fill

Deceased human remains are often buried as a forensic countermeasure or method of disposal by homicide perpetrators. Owing to this, the excavation of clandestine grave sites is a task that forensic crime scene teams may only encounter a few times a year. Not all crime scene units have specialised teams for this task, and even those that do, may not have specific protocols for the optimal recovery of forensic traces retained within grave fill as procedures such as sieving require optimisation for the specific soil conditions of the jurisdiction. This study aimed to define the optimal sieving conditions for a sandy environment when searching for minute traces of paint, glass, hair and fibres. Furthermore, this study justifies the practice of retaining grave fill and examining it under controlled laboratory conditions, rather than in-situ adjacent to the grave site. The results demonstrate that using sieve mesh sizes as fine as 0.1 mm can recover up to 82% of the deposited traces and almost all paint, hair and glass traces. The processing of grave fill in the laboratory lead to increased yield of forensic evidence, which on a case-basis may warrant the increased time needed. These findings merit consideration for clandestine grave crime scenes where evidence is scarce or the case is likely to become cold.

Portable gas chromatography-mass spectrometry method for the in-field screening of organic pollutants in soil and water at pollution incidents

Environmental pollution incidents generate an emergency response from regulatory agencies to ensure that the impact on the environment is minimised. Knowing what pollutants are present provides important intelligence to assist in determining how to respond to the incident. However, responders are limited in their in-field capabilities to identify the pollutants present. This research has developed an in-field, qualitative analytical approach to detect and identify organic pollutants that are commonly detected by regulatory environmental laboratories. A rapid, in-field extraction method was used for water and soil matrices. A coiled microextraction (CME) device was utilised for the introduction of the extracted samples into a portable gas chromatography-mass spectrometry (GC-MS) for analysis. The total combined extraction and analysis time was approximately 6.5 min per sample. Results demonstrated that the in-field extraction and analysis methods can screen for fifty-nine target organic contaminants, including polyaromatic hydrocarbons, monoaromatic hydrocarbons, phenols, phthalates, organophosphorus pesticides, and organochlorine pesticides. The method was also capable of tentatively identifying unknown compounds using library searches, significantly expanding the scope of the methods for the provision of intelligence at pollution incidents of an unknown nature, although a laboratory-based method was able to provide more information due to the higher sensitivity achievable. The methods were evaluated using authentic casework samples and were found to be fit-for-purpose for providing rapid in-field intelligence at pollution incidents. The fact that the in-field methods target the same compounds as the laboratory-based methods provides the added benefit that the in-field results can assist in sample triaging upon submission to the laboratory for quantitation and confirmatory analysis.

Environmental damage compensation for illegal solid waste dumping in China

China aims to improve its system for pursuing environmental damage compensation environmental violation cases. To hold violators accountable, China has an effective system for the identification and assessment (I&A) of environmental damage. This study selected a typical case of the illegal dumping of solid waste (IDSW) in China to analyze the causes, the degree, and characteristics of environmental damage, focusing on components such as the physical quantification and valuation of damage. The findings were as follows: (1) Compensation claimants and obligors consider baseline damage confirmation and causality analysis key components of I&A. (2) The I&A process for a specific case needs to focus on key nodes such as the type, location, and duration of IDSW. (3) Restraining IDSW requires accurately quantifying the physical and value-related losses caused by solid waste dumping. (4) In the selected case study, the damage from environmental contamination caused by the IDSW incident amounted to 3938,990 yuan, including an environmental damage value of 3651,990 yuan and a transaction cost of 287,000 yuan. Both parties accepted the I&A calculation process in this case, and the desired punishment effect was achieved. Hence, the case study demonstrated that accurate I&A is the technical basis for environmental damage compensation. Thus, in the future, more attention should be paid to the role of scientific and technological means and knowledge reserves in the I&A of environmental damage.

Forensic botany: who?, how?, where?, when?

Plants are a good source of biological forensic evidence; this is due to their ubiquity, their ability to collect reference material, and their sensitivity to environmental changes. However, in many countries, botanical evidence is recognised as being scientifically. Botanical evidence is not mostly used for perpertration, instead it tends to serve as circumstantial evidence. Plant materials constitute the basis, among others, for linking a suspect or object to a crime scene or a victim, confirming or not confirming an alibi, determining the post-mortem interval, and determining the origin of food/object. Forensic botany entails field work, knowledge of plants, understanding ecosystem processes, and a basis understaning of geoscience. In this study, experiments with mammal cadavers were conducted to determine the occurence of an event. The simplest criterion characterising botanical evidence is its size. Therefore, macroremains include whole plants or their larger fragments (e.g. tree bark, leaves, seeds, prickles, and thorns), whereas microscopic evidence includes palynomorphs (spores and pollen grains), diatoms, and tissues. Botanical methods allow for an analysis to be repeated multiple times and the test material is easy to collect in the field. Forensic botany can be supplemented with molecular analyses, which, although specific and sensitive, still require validation.

Untargeted SPME-GC-MS Characterization of VOCs Released from Spray Paint

Paints are a common form of physical evidence encountered at crime scenes. This research presents an optimized method for the untargeted analysis of volatile organic compounds (VOCs) in spray paint using solid-phase microextraction-gas chromatography-mass spectrometry (SPME-GC-MS). The presence and persistence of VOCs were monitored in 30 minute intervals, over a 4 hour period, in a triplicate time study. As predicted, spray paint solvents are lost to the environment readily, whereas few VOCs remained present in the headspace in low concentrations beyond 4 hours. The VOCs that were observed to have the highest persistence in the headspace were aromatic compounds and those with longer hydrocarbon chains. We present this study in a forensic science context and suggest that the interpretation of the results may be useful for forensic applications in establishing a time since deposition of a spray-painted surface.

Soil as a tool of revelation in forensic science: a review

Soil contains diverse and complex natural elements having physical, chemical, mineralogical and biological components. Soil being a transferable physical component (it can be transferred from one location to another with the help of shoes, tires, clothes, tools etc.), acts as a tool of forensic investigation to correlate a specific crime scene with criminal suspects. A variety of techniques and combinations of methods can be used to discriminate soil from different geographical locations. The present review highlights various analytical techniques (ATR-FTIR, pyGC-MS, SEM-EDX, ICP-MS/OES and XRD) for soil analysis (colour comparison, texture and particle size determination, density gradient methods and organic matter estimation) and discusses some of the famous cases solved with soil trace evidence. The objective of the present study is to provide an overview of the importance of soil as physical evidence in forensic science based on literature analysis that will help forensic scientists and researchers to select appropriate methods to discriminate different soil samples. This article reviews various analytical techniques used to differentiate soils and provides compiled information regarding soil as trace evidence in order to help academicians, researchers and forensic soil scientists.

Rapid on-site identification of hazardous organic compounds at fire scenes using person-portable gas chromatography-mass spectrometry (GC-MS)-part 2: water sampling and analysis

Building and factory fires pose a great risk to human and environmental health, due to the release of hazardous by-products of combustion. These hazardous compounds can dissipate into the environment through fire water run-off, and the impact can be immediate or chronic. Current laboratory-based methods do not report hazardous compounds released from a fire scene at the time and location of the event. Reporting of results is often delayed due to the complexities and logistics of laboratory-based sampling and analysis. These delays pose a risk to the health and wellbeing of the environment and exposed community. Recent developments in person-portable instrumentation have the potential to provide rapid analysis of samples in the field. A portable gas chromatograph-mass spectrometer (GC-MS) was evaluated for the on-site analysis of water samples for the identification of hazardous organic compounds at fire scenes. The portable GC-MS was capable of detecting and identifying a range of volatile and semi-volatile organic compounds in fire water run-off, and can be used in conjunction with conventional laboratory analysis methods for a comprehensive understanding of hazardous organics released at fire scenes. Deployment of this portable instrumentation provides first responders with a rapid, on-site screening tool to appropriately manage the run-off water from firefighting activities. This ensures that environmental and human health is proactively protected.