Forensic Gemmology is a branch of Forensic Science where the analysis of gemstones has legal implications, which cannot be set aside, improvised, or, even worse, done with approximation. Local and world markets and archaeological sites can currently encounter a wide range of gemmological objects that are incorrectly declared, treated, or classified. Materials in question are made by also using the latest technologies. Occasionally, cases are brought to court regarding the value of a precious gem in addition to its "authenticity," which often, to be resolved, require complex preparation. Therefore, keeping in mind the significance of gemstone identification, here are specific methodologies discussed to test the authenticity of the gemstones and to find out whether the gemstones are authentic or not. Modern challenges also concern determining whether gemstones were extracted under ethical conditions and determining whether gemstones are of synthetic or natural origins. Thus, forensic examination of gemstones becomes very difficult if proper procedures are not outlaid. The problems that need to be addressed at the international level remain relevant, for instance, creating a standard scheme for determining the ethical origin of colored gemstones, similar to the one existing in the diamond market.

How to cite: Spoto, S. E.: Old and modern challenges of Forensic Gemmology, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-13026, https://doi.org/10.5194/egusphere-egu23-13026, 2023.

In criminal cases of clandestine homicide graves, the criminal behavior and mental map of an offender may be influenced by several geographical, botanical, and geological features. Among these factors, diggability assumes for a concealer a predominating role in the concealment act because an easy and efficient digging of a hole requires that the ground is diggable. The diggability (the ease and efficiency with which soils and sediments may be dug and reinstated in a grave) may vary from very easy to difficult, and forensic geologists may qualitatively and relatively evaluate it by using a T-metal bar for offensive and defensive search purposes. Results of a diggability survey were processed in the GIS platform, reconstructing contour maps, Inverse Distance Weighting, Kriging, and Thin Plate Spline with Tension maps of a crime scene. The interpolation of the data by Thin Plate Spline with Tension rendered the best results. The diggability survey demonstrated that the pit fell in a suitable area for concealment, being one of the easiest diggable and thick sectors of the search area.

How to cite: Somma, R.: Diggability field survey for the assessment of the most suitable site for a clandestine homicide grave, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-20, https://doi.org/10.5194/egusphere-egu23-20, 2023.

Land reclamation is a significant environmental and economic issue. Nowadays, there is a need to restore industrial areas to a state as close to nature as possible. Therefore, it is essential to monitor the condition of soils in a quick and non-invasive way. In southern Poland, the mining industry led to the creation of diverse waste dumps like post-mining waste, tailings from flotation, or Zn-Pb wash waste dumps. The research area covers the industrial waste dumps in Olkusz, Bytom and Piekary Śląskie. For the study, soil samples were taken from 1 m soil pits to determine the migration of pollutants into the soil profile. Additionally, waste dumps contacting the soils were sampled (from 0.5 m deep pits). The total organic carbon and sulphur were determined using Eltra Elemental Analyser CS530, while the composition of the total extracts was analyzed using Agilent gas chromatograph 7890A, with a DB-5 column coupled with a mass spectrometer 5975 C XL MDS. The total concentration of trace elements was determined using atomic absorption spectrometry in an acetylene-air flame (Analyst 400, Perkin Elmer). The ERT measurements were performed using LUND electrical imaging system with SAS 4000 Terrameter produced by ABEM Malå (Guideline Geo).

The samples contain av. 3.7 wt. % TOC and 0.4 wt. % TS. In GC-MS chromatograms, the Bytom and Piekary Śląskie samples show a higher PAHs abundance than the Olkusz samples. In soil profiles near waste dumps, a higher abundance of PAHs was found not only in the surface layer but also in samples to 0.75 m depth. In soil profiles away from the landfill, a higher abundance of PAHs was found only to 0.5 m depth. The PAHs abundance was decreased below 0.5 m depth, and even some of the PAHs weren't found. The high PAHs abundance even at a depth of up to 1m was observed in soil profiles under a waste layer. In samples, the concentrations of trace elements are higher than the limit values (Cd 1.1 to 135.7, Pb 17 to 12407 and Zn 19 to 28903 mg/kg). Soil contamination and its spatial diversity with trace elements in the mining area can be successfully located and studied using ERT measurements. The impact of soil pollution was observed on the geoelectric cross-sections in the form of reduced electrical resistivity associated with an elevated trace element content compared to the unpolluted area. The differentiation of the electrical resistivity was related in particular to the sites of surface runoff from the waste dump. The sediment washed out from the waste dump changed the physical characteristics of the soil and lowered the electrical resistivity of the native geology. The results suggest that the trace elements and toxic organic compounds in wastes are mobilised by surface runoff and the infiltration of rainwater into the ground.

Acknowledgements

The financial support of the National Science Centre, grant No 2017/27/B/ST10/00680 is gratefully acknowledged.

Presentation preference: poster on-site in Vienna

How to cite: Szram, E., Kondracka, M., Fabiańska, M., and Marynowski, L.: Soil degradation caused by post-mining and post-metallurgical waste - detection using gas chromatography–mass spectrometry (GC-MS) and electrical resistivity tomography (ERT), EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-5477, https://doi.org/10.5194/egusphere-egu23-5477, 2023.

In the 1978, Gianni Lombardi and Valerio Giacomini, two Italian experts in forensic geology and botany, respectively, were involved by the judicial authority for analysing the sands and plant remains found in the clothing and moccasins of the honorable Aldo Moro, kidnapped and killed by terrorists. Experts had to determine the site where this material transfer occurred.

As demonstrated by the analyses carried out by these experts, plant taxonomists can give useful information in forensic analyses especially for events occurring outdoor. Small plant traces spread in quantity, like pollens, spores, thorns, seeds and small fruits, may easily transfer to the clothing and footwear of people or to the same human body, moving outdoor in the countryside.

In 2020, 42 years later, the authors of this research were involved by the judicial systems to reconstruct the events related to the disappearance of two persons, in the Sicilian countryside, found cadavers a few days after in a site near the last sighting of them.

The research focused on the morphological description of thorns, other pointed structures, and seeds produced by plants thriving in the scene of events. For simplicity, it was chosen to use the generic term "thorns" to indicate pointed plant structures, although aware that the term "prickle" should have been used for epidermal structures, “thorns” strictly for stem-derived structures, and "spines" for other structures derived from leaves, petioles or stipules.

A photographic atlas of thorns and seeds was produced with the species found in the scene of the events. A comprehensive description of plants as they appeared in situ as well as of their thorny appendices was made, and explanatory pictures were captured, both in situ and under the stereoscopic microscope in the laboratory. The extensive biometric analysis made on thorns and seeds of all collected species in the scene of events was recorded.

Soil traces and microtraces of forensic samples of unknown origin (from the victims’ bodies and their belongings) were investigated for the presence of thorns or thorn fragments and seeds, which were then compared with those recorded in the atlas.

The organic component (vegetal elements) of the forensic geological traces from victims and their belongings was predominant in quantity over the inorganic one.

Comparative observations allowed to identify hundreds of thorns and thorn fragments and several hundreds of seeds found on the clothes and footwear of both victims, as plants thriving in the area under investigations. Basing on the punctual distribution of individual plants, the analysis of thorn traces and seeds was useful, together with geological analyses on sands and clay minerals, in reconstructing the path of the victims in the hours immediately preceding their death and, therefore, provided valuable information to the investigating authorities.

How to cite: Mondello, F., Morabito, M., and Somma, R.: Holistic approach in the forensic analysis of geological trace evidence: as Forensic Botanists and Geologists may help judicial investigations , EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-6304, https://doi.org/10.5194/egusphere-egu23-6304, 2023.

The search for homicide graves is a very strenuous activity that may lead to the identification of the burial site if it is planned based on articulated scientific approaches considering several aspects of forensic sciences. Moreover, another difficult task in such criminal cases may be the estimation of the Post-Mortem Interval (PMI) of the victim. Discrepancies between PMI estimation through entomological studies and other evaluations may be. This inconsistency is at the base of the necessity to examine and well understand the human decay process of human beings and the decay consequences in the surrounding environmental context. It is noteworthy that several processes may occur on the surrounding site the burial. Phenomena as a depression, a different growth of plants, or the occurrence of peculiar insect associations may be observed on the grave, due to the body’s decay, and the body fluids release in the underground. These aspects may be analysed in experimental fields where pig carcasses, usually used as analogues for the human cadavers, are inhumated in holes dug by means of hand instruments (pick and shovel) or mechanical excavators. These sites may be monitored by applying geological, geophysical, geochemical, and geomatic methods, as well as entomological and botanical characterization of the insects and flora, respectively. The present research is devoted to plan, analyse and monitoring of a simulated experimental field in Malta, where a simulated grave containing a pig carcass will be prepared. The research project is dedicated to geophysical and geomatic surveys to be realized before the excavations and during the project for monitoring the depression development and the shape and dimensions of the leachate plume. Geophysical methods consist of ERT tomographies, seismic and georadar profiles, parallel and orthogonal to the graves. Geological investigations are focused on characterizing the pedogenic profile and the composition, texture, and structure of the soil/sediment. Entomological research is devoted to identifying insect species typically related to body decay. Ideally and in addition to the above, botanical surveys are aimed at defining the main species and differences in the plant growth. The reconstructed evolution of the burial environment may be investigated to better assist criminal investigations into the definition of the PMI in recognition of a burial site and other significative criminological and criminalistic data.

How to cite: D’Amico, S., Byrd, J. H., Colica, E., Formosa, S., Somma, R., Tagliabue, G., and Trombino, L.: Forensic geosciences investigations on experimental fields, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-8782, https://doi.org/10.5194/egusphere-egu23-8782, 2023.

In Forensic Geology, Environmental Forensics is devoted to ascertaining contaminants in the soil/subsoil, surface waters, and groundwaters. In such cases, forensic geologists usually accomplish activities concerning geological, hydrogeological, geochemical, and geophysical research to individuate the source of the contaminant substance and discover if this latter depends on anthropogenic or natural origins.

Preliminary chemical data on groundwaters from some areas of the Peloritani Mountains showed anomalous high contents of fluoride F^-, a halogen element in the atmosphere, sea, fresh waters, and minerals. Natural sources of fluoride in the groundwaters are volcanic gas, the sea, and minerals. Fluoride is an essential component in around 300 minerals, among which the most diffused are fluorite and fluorapatite. A significant chemical feature of the ions of fluoride is that they have the same charge as the hydroxyl group OH^- and present an ionic radius very similar to OH^-. These chemical characteristics make it possible that F^- may readily substitute the hydroxyl group in minerals such as micas, X₂Y₄-₆Z₈O₂₀(OH,F)₄.

Most of the collected groundwaters in the present research were hosted in aquifers formed by Variscan high-grade metamorphic rocks provided with fracture permeability and in aquifers made up of Tertiary to Quaternary siliciclastic deposits with porosity permeability. These aquifers have a silicate composition and are rich in biotite. Among micas, biotite is the most diffused mafic mineral in the high-medium grade metamorphic rocks (augen gneiss, gneiss, mica schists) of the Peloritani Mountains. This mineral is also widespread in weathered monomineralic lithoclasts of siliciclastic deposits (Miocene, middle to upper Pleistocene, Holocene to Actual clastic deposits) deriving from dismantling the chain's metamorphic rocks.

Previous studies on biotite from acid plutonic rocks of India demonstrated that fluoride contents might reach a concentration up to 7 wt%. Biotite mica may be likely responsible for the natural fluoride contamination of some of the studied groundwaters, in some cases also commercially exploited in the past.

WHO suggests that the F^- concentration in the drinking waters must range between 700 and 1500 µg/l depending on the different climatic zones. Concentrations over 1500 µg/l in Italian drinking waters are prohibited and dangerous for public health.

The present research carried out in the Peloritani Mountains is devoted to: i) defining the actual geographical extent of the identified F^- anomaly; ii) studying the water/rock interactions to ascertain if the leaching of F^- from biotite mica, present in the high-grade metamorphic rocks and siliciclastic deposits, may be the natural phenomenon responsible for the ascertained fluoride contamination; iii) search for possible other causes of F^- contamination as the salt wedge intrusion in the groundwaters of the coastal areas.

How to cite: Crea, F., Alessandrello, C., Parello, F., Somma, R., and Spoto, S. E.: Find the culprit, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-5500, https://doi.org/10.5194/egusphere-egu23-5500, 2023.

The multidisciplinary approach in forensic science led to the development of geology and botany as predictive forensic applications (forensic geology – forensic botany) aimed at analyzing and studying the crime scene for the "solving" of the criminal hypothesis. Over the past fifteen years, the study of plant DNA has been used in forensics science to discriminate the place of origin of plant material found at a crime scene, to identify poisonous vegetable species, as a forensic marker in all cases where determining geographic origin is essential to investigative leads, missing person cases, and intelligence application (Bell et al., 2015), in the identification of Cannabis as support of law authorities in fighting drug abuse and global trafficking. These specific topics to date made it possible to: distinguish a primary crime scene from a secondary one, link a suspect to the crime scene, and determine the date of death. Findings of plant material can be examined through chemical analysis, morphological analysis, DNA analysis, PCR and electrophoresis. Comparative studies may be carried out among the plant remains collected from the victim and suspect and plant sampled on the event scene in order to trace the place where the plant transfer occurred. The analysis of the international literature presented through this review shows the importance of further developments in plant DNA analysis, growing and expanding a global database containing the plant DNA barcode, and implementing specific guidelines for the collection and sampling procedures of forensic samples.

How to cite: Sapienza, D., Baldino, G., Lo Piccolo, I., Somma, R., Ventura Spagnolo, E., Mondello, C., Gualniera, P., and Asmundo, A.: Overview in forensic purpose and application of plant DNA, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-3869, https://doi.org/10.5194/egusphere-egu23-3869, 2023.

Legal cases involving human and animal envenomizations may be encountered by the medicolegal investigator.  Such cases are often difficult due to lack of physical evidence and analytical difficulty.  The development and use of an interdisciplinary approach and standardized protocol involving experts in environmental and life sciences (toxicology, legal medicine, entomology, veterinary forensic science, biology, geography, geology, and meteorology) may improve the documentation, collection, and presentation of physical evidence in court.  This information can be utilized to develop and optimize new protocols for toxicological screenings for application in human and animal cases.  In such cases, the scientific background of coroners and police experts may not be sufficient to correctively delineate the environmental features of the territory that may be typical of certain species of venomous fauna present in the scene of the events. Therefore, protocols providing complete information concerning the environment of the scene and detail of the events together with exam protocols, sample collection, tissue preservation, and testing/analysis are needed. This holistic approach could enhance the ability to detect toxins involved in envenomizations to better manage forensic science and legal cases. 

How to cite: Byrd, J., Sapienza, D., Schaer, M., Stern, A., Somma, R., Sutton, L., and Trombetta, D.: Procedures for the documentation and collection of physical evidence from human and animal envenomization cases., EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-70, https://doi.org/10.5194/egusphere-egu23-70, 2023.