Search

Forensic entomology is primarily concerned with the estimation of time since death and involves determination of the age of immature insects colonising decomposing remains. Accurate age determination of puparia is usually accomplished by dissection, which means destructive sampling of evidence. As part of improving abilities to correctly identify species and developmental age, it is highly desirable to have available non-destructive methods. In this study, we acquired external hyperspectral imaging (HSI) data (77 spectral bands, 389-892 nm) from the dorsal and ventral sides of individual puparia of two species of blowfly (Diptera: Calliphoridae), Calliphora dubia Macquart 1855 and Chrysomya rufifacies Macquart 1842. Puparia were dissected to determine the presence/absence of eight internal morphological development characteristics (legs, wings, labella, abdominal segments, antennae, thoracic bristles, orbital/facial bristles and eye colour and arista). Based on linear discriminant analysis and independent validation of HSI data, reflectance features from puparia could be used to successfully (1) distinguish the two species (classification accuracy = 92.5 %), (2) differentiate dorsal and ventral sides of puparia (classification accuracy C. dubia = 81.5 %; Ch. rufifacies = 89.2 %) and (3) predict the presence of these morphological characteristics and therefore the developmental stage of puparia (average classification accuracy using dorsal imaging: C. dubia = 90.3 %; Ch. rufifacies = 94.0 %). The analytical approach presented here provides proof of concept for a direct puparial age relationship (i.e. days since the onset of pupation) between external puparial reflectance features and internal morphological development. Furthermore, this approach establishes the potential for further refinement by using a non-invasive technique to determine the age and developmental stage of blowflies of forensic importance. [ABSTRACT FROM AUTHOR]

Determining the minimum postmortem interval (minPMI) from an entomological perspective relies mainly on development data recorded for various species of flies collected from a crime scene or suspicious death. This study focused on the larval and pupal development of Lucilia sericata (Meigen), with an emphasis on the changes of the external morphology of the puparium and its pupal content throughout the duration of metamorphosis. Colonies of L. sericata were reared on 3 types of swine tissue (skeletal muscle, liver tissue, and heart tissue) at 2 different temperature regimes; 24 ± 1 °C and 30 ± 1 °C. The overall developmental time, larval width and length, and inner and outer pupal morphology changes were observed and recorded. The results show that: (i) temperature significantly influenced overall development time, as well as changes in larval width and length, but this effect was not dependent on tissue type; (ii) larval development duration was longest on heart tissue, and shortest on skeletal muscle for both temperatures; and (iii) pupation was longest for larvae reared on skeletal muscle at 24 ± 1 °C, and on liver tissue at 30 ± 1 °C, while those larvae reared on liver tissue at 24 ± 1 °C and heart tissue at 30 ± 1 °C had the shortest pupation period. A seven-character checklist plus 4 landmark stages were developed comprising the external morphology of the puparium and pupal content changes of L. sericata. In conclusion, the study provides larval and pupal development timetables, as well as checklists and photo guides for pupal character development that may be useful for future postmortem determinations., (© The Author(s) 2024. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For commercial re-use, please contact reprints@oup.com for reprints and translation rights for reprints. All other permissions can be obtained through our RightsLink service via the Permissions link on the article page on our site—for further information please contact journals.permissions@oup.com.)

Considering the growing importance of microbiome analyses in forensics for identifying individuals, this study explores the transfer of the skin microbiome onto clothing, its persistence on fabrics over time, and its transferability from the environment and between different garments. Furthermore, this project compares three specific QIAGEN microbiome extraction kits to test their extraction efficiency on fabric samples. Additionally, this study aims to check if these extracts contain human DNA, providing a chance to obtain more information from the same evidence for personal identification. The results obtained show: (1) variations in the skin microbiome between the volunteers, potentially due to their different sex; (2) differences in microbial composition between worn and unworn clothing; (3) the influence of the environment on the microbial signature of unworn clothing; (4) the potential use of certain phyla as biomarkers to differentiate between worn and unworn garments, even over extended periods; (5) a tendency towards extraction biases in the QIAampMP ® DNA microbiome kit among the three tested ones; and (6) none of the extraction kits allow for the typing of human genetic profiles suitable for comparison. In conclusion, our study offers supplementary insights into the potential utility of time-transferred microbiome analysis on garments for forensic applications.

The number of foreign citizens resident in Italy is approximately 5 million, making them the 8.7% of the resident population of the country. However, over the past 20 years, foreign citizens accounted for 24% of the total number of defendants involved in homicides, especially associated with robbery, disputes and assaults, generally connected to prostitution. Investigations of cases in the context of culturally diverse or minority communities can be particularly complex. This is due to the education, the cultural background and the cohesiveness of the community, alongside a negative view of law enforcement. These factors determine a relatively low resolution rate of these violent crimes in these communities. The investigation of the suspicious death of an Indian citizen living in Italy is presented in this paper. The body was discovered in a cattle shed, and despite the initial assumption of an accidental death, the cranial lesions were not consistent with the view that the death was caused by a kick by a cow. The results of a multidisciplinary analysis, including imaging, pathology, toxicology and veterinary forensics, were directed towards a homicide, with the manner of death ultimately filed as undetermined. During the course of the investigation, the collaboration between law enforcement and the community was thwart with difficulty, and as a consequence this case is currently unsolved. In order for law enforcement to continue to play a constructive and supportive role, it is imperative that every country invest in civil education of local population and of any ethnic groups, minorities and culturally diverse people., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2022 The Author(s).)

The Coronavirus disease 2019 (COVID-19) is spreading around the world, representing a global pandemic. In this context, governments from around the world suspended almost all education, industry and business activities, alongside restricting the movement of people. Nevertheless, during this period, the activity of the law enforcement and forensic investigators never stopped. At present, guidelines regarding forensic autopsies of SARS-CoV-2 virus-positive cases and the handling of potentially infected biological samples are available in literature. However, less attention has been given to the development of specific adjustments to the existing crime scene investigation protocols and procedures for this exceptional time. This manuscript aims to share the methods and strategies adopted for the investigation of high priority criminal cases during the pandemic. Furthermore, other pandemic-related processes are critically explored, in order to propose adjustments for any forensic services to be prepared to face similar challenges in the future. The overall goal of this manuscript is to provide a summary of the main measures and the procedures developed to make the operations possible, while safeguarding the technicians in the field and the activity in the forensic laboratory. In order to minimize the risk of infection for personnel, adjustments to the standard practice have been proposed for each of the different phases of crime scene management, i.e. CSI call policy, equipment preparation, working groups, procedure at the scene, chain of custody and analyses of the evidence at the forensic lab. As this is a current study, based on limited cases and limited sources in the literature, changes and updates to the indications provided in this paper may be needed in the near future, according to new virological data epidemiological trends., (Copyright © 2021 The Chartered Society of Forensic Sciences. Published by Elsevier B.V. All rights reserved.)

Next-generation sequencing (NGS) studies show that mosquito and tick microbiomes influence the transmission of pathogens, opening new avenues for vector-borne pathogen control. Recent microbiological studies of Australian ticks highlight fundamental knowledge gaps of tick-borne agents. This investigation explored the composition, diversity and prevalence of bacteria in Australian ticks ( n  = 655) from companion animals (dogs, cats and horses). Bacterial 16S NGS was used to identify most bacterial taxa and a Rickettsia -specific NGS assay was developed to identify Rickettsia species that were indistinguishable at the V1-2 regions of 16S . Sanger sequencing of near full-length 16S was used to confirm whether species detected by 16S NGS were novel. The haemotropic bacterial pathogens Anaplasma platys , Bartonella clarridgeiae , " Candidatus Mycoplasma haematoparvum" and Coxiella burnetii were identified in Rhipicephalus sanguineus ( s.l .) from Queensland (QLD), Western Australia, the Northern Territory (NT), and South Australia, Ixodes holocyclus from QLD, Rh. sanguineus ( s.l. ) from the NT, and I. holocyclus from QLD, respectively. Analysis of the control data showed that cross-talk compromises the detection of rare species as filtering thresholds for less abundant sequences had to be applied to mitigate false positives. A comparison of the taxonomic assignments made with 16S sequence databases revealed inconsistencies. The Rickettsia -specific citrate synthase gene NGS assay enabled the identification of Rickettsia co-infections with potentially novel species and genotypes most similar (97.9-99.1%) to Rickettsia raoultii and Rickettsia gravesii . " Candidatus Rickettsia jingxinensis" was identified for the first time in Australia. Phylogenetic analysis of near full-length 16S sequences confirmed a novel Coxiellaceae genus and species, two novel Francisella species, and two novel Francisella genotypes. Cross-talk raises concerns for the MiSeq platform as a diagnostic tool for clinical samples. This study provides recommendations for adjustments to Illumina's 16S metagenomic sequencing protocol that help track and reduce cross-talk from cross-contamination during library preparation. The inconsistencies in taxonomic assignment emphasise the need for curated and quality-checked sequence databases., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2021 The Author(s).)

After death, the body begins decomposition, a process that starts with the breakdown of organic matter and typically leads to the complete degradation of a body. Such a process is highly affected by (micro and macro) environmental factors of intrinsic and extrinsic nature. Adipocere is a substance formed from the decomposition of adipose tissue and represents a disruption to the typical decomposition process. Such disruption causes decomposition to slow or arrest completely, placing a body into a state of preservation, and determines complications in the estimation of the time since death (Post-Mortem Interval, PMI). While several studies have been performed on the nature, the formation and the degradation of adipocere, there is still no reliable model to assess the PMI of a body exhibiting it. Case studies are an important source to aid pathologists and investigators during a case. This review presents a summary and an update on the knowledge surrounding the chemistry and the factors affecting adipocere formation and degradation, the timing and the distribution of adipocere throughout a body, and the techniques used to investigate it. Furthermore, a table of the most important case studies involving adipocere since 1950, several images and descriptions of recent cases and operational considerations for the best practice at the crime scene and autopsy are presented to be used as a reference to facilitate forensic professionals in adipocere cases., (Copyright © 2020. Published by Elsevier Ltd.)

Entomotoxicology studies employ analytical methods and instrumentation to detect chemical substances in carrion insects feeding from the decomposing tissues. The identification of such chemicals may determine the cause of death and may be used for the estimation of the minimum time since death. To date, the main focus of entomotoxicological studies has been the detection of drugs, whereas little information concerns the effects of pesticides on blowflies. Pesticides are generally freely available and more affordable than drugs but they can also be a home hazard and an accessible candidate poison at a crime scene. A QuEChERS extraction method followed by Gas chromatography-mass spectrometry (GC-MS) analysis was developed for the detection of α- and β-endosulfan (organochlorine insecticide and acaricide) in Calliphora vomitoria L. (Diptera: Calliphoridae) and validated. Furthermore, the effects of endosulfan on the morphology, development time and survival of the immature blowflies were investigated. Larvae were reared on liver substrates homogeneously spiked with aliquots of endosulfan corresponding to the concentrations found in body tissues of humans and animals involved in endosulfan poisoning. Results demonstrated that the combination of QuEChERS extraction and GC-MS provide an adequate methods to detect both α- and β-endosulfan in blowfly immatures. Furthermore, the presence of α- and β-endosulfan in the food source 1) prevented C. vomitoria immatures reaching the pupal instar and, therefore, the adult instar at high concentrations, 2) did not affect the developmental time of blowflies at low concentrations 3) affected the size of immatures only at high concentrations, resulting in significantly smaller larvae., (© The Author(s) 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Forensic entomology is primarily concerned with the estimation of time since death and involves determination of the age of immature insects colonising decomposing remains. Accurate age determination of puparia is usually accomplished by dissection, which means destructive sampling of evidence. As part of improving abilities to correctly identify species and developmental age, it is highly desirable to have available non-destructive methods. In this study, we acquired external hyperspectral imaging (HSI) data (77 spectral bands, 389-892 nm) from the dorsal and ventral sides of individual puparia of two species of blowfly (Diptera: Calliphoridae), Calliphora dubia Macquart 1855 and Chrysomya rufifacies Macquart 1842. Puparia were dissected to determine the presence/absence of eight internal morphological development characteristics (legs, wings, labella, abdominal segments, antennae, thoracic bristles, orbital/facial bristles and eye colour and arista). Based on linear discriminant analysis and independent validation of HSI data, reflectance features from puparia could be used to successfully (1) distinguish the two species (classification accuracy = 92.5 %), (2) differentiate dorsal and ventral sides of puparia (classification accuracy C. dubia = 81.5 %; Ch. rufifacies = 89.2 %) and (3) predict the presence of these morphological characteristics and therefore the developmental stage of puparia (average classification accuracy using dorsal imaging: C. dubia = 90.3 %; Ch. rufifacies = 94.0 %). The analytical approach presented here provides proof of concept for a direct puparial age relationship (i.e. days since the onset of pupation) between external puparial reflectance features and internal morphological development. Furthermore, this approach establishes the potential for further refinement by using a non-invasive technique to determine the age and developmental stage of blowflies of forensic importance.