Journal of forensic sciences最新文献

The present research examined the recovery rates of skeletal elements from forensic anthropology case report inventories at the Office of the Chief Medical Examiner, Massachusetts, with cases from 1979 through 2023 and from five contexts: terrestrial ground surface (n = 65), marine/freshwater (n = 49), cemetery burial (n = 67), recent burial (n = 5), and previous anatomical teaching specimens (n = 38). Element representation was highest in recent burial and terrestrial environments, followed by previous anatomical remains, marine/freshwater environments, and lowest in cemetery environments. The cranium was the highest represented element in all contexts (between 45.0% [marine] and 100.0% [burial]), and most contexts followed the same general patterns of element representation with high representation of the long bones, higher representation of the lower axial skeleton (os coxae, lumbar vertebrae) vs. the thoracic and cervical vertebrae, and overall low representation of the hyoid, sternal body, patellae, and elements of the hands and feet. These recovery rates are related to the typical taphonomic agencies encountered in these environments, recovery context and methods, and inherent bone properties. Knowledge of these differing patterns may aid in the determination of the origin of unknown remains, highlight recovery and identification methods in need of greater focus, and support the utilization of forensic anthropologists in medicolegal casework.

The field of forensic archaeology has been primarily associated with the search, location, and excavation of clandestine graves, and thus, other deposition types have been commonly neglected in research. Current literature typically addresses the use of traditional methods implemented for the excavation and recovery of human remains from clandestine graves but fails to provide the same for surface scatter scenes. This study aimed to explore the documentation of such scenes through the integration of traditional archaeological techniques, geophysical surveying techniques, and GIS. A mixed method study was created and utilized in three different simulated scatter scenes, allowing the qualitative and quantitative scope of GIS to be examined and assessed. The techniques were utilized successively and iterated until all simulated scenes had been documented. Within this study, terrain was the independent variable—this was nonrandomized and chosen to best suit sites where scatter scenes are most prevalent. Results demonstrated GIS to be an effective method in the documentation of contextual data at a forensic surface scatter scene, providing both qualitative and quantitative data. Such findings aid in understanding the admissibility of each technique in court and its impact on a case when presented as evidence. This research revealed that further exploration of surveying techniques in sites other than clandestine graves is necessary for forensic archaeology practice.

The genomic analysis of biological material from artworks can be used to guide curation, preservation, and restoration. Additionally, human DNA recovered from artworks may provide other insights. However, the recovery of biological samples from artworks is dependent on the sampling technique used and the media from which the biological materials are recovered. The ideal sampling method should be noninvasive, yet robust. We studied five artworks on paper and compared three sampling methods, each with increasing degrees of invasiveness. Minimally invasive swabbing techniques collect samples from the surface, whereas more aggressive techniques such as wet vacuuming were expected to yield more biological material from within the support media and more likely to produce authentic DNA from the artwork. We report a comparison of collection techniques to generate microbial DNA sequence data, the conserved human gene RNase P, and Y-STRs from artworks on paper. We observed that wet vacuuming resulted in higher DNA recovery than double swabbing and core punches. Diverse microbial populations existed on the corners and centers of the five artworks studied, but the distribution of the total biomass was relatively even across the surfaces of the works sampled. Studies of peripheral regions, where sampling is less likely to cause alterations to the artwork, could thus yield useful results in microbiome and human DNA studies. These results provide a framework for sampling artworks on paper to obtain biological material. The methods described may provide microbiome identification to facilitate restoration and preservation, and might also contribute to the determination of provenance.

With the increasing trend of digitization of business processes and personal communication across the globe, digital documents of intrinsic value continue to be created. Whereas the questioned document examination (QDE) field of forensic science deals with the examination of “physical” documents potentially disputed in a court of law, there are no developed approaches for handling questioned digital documents (QDDs). Although techniques that address related problems such as identifying document types and image forensics exist, concrete strategies for analyzing questioned “digital” documents still need to be developed. This paper focuses on developing methods to examine QDDs that are customized from a database, due to the versatile use of customized documents in many areas. As a basis for our approach, we make the case for the need to develop analysis techniques for a digital counterpart of QDE which we term Questioned Digital Document Examination (QDDE). We posit that there is a benefit in considering digital aspects of forensic science disciplines where the questions answered by the discipline are clear, from a digital perspective. The paper describes some of the aspects that can be considered in the domain of question digital document examination. In designing methods for QDDE, we discuss the process of document recreation and describe the feasibility of our recreation process in different scenarios. Our experiments show that an alternative approach of considering digital aspects from a well-defined physical domain is worthwhile. It also supports the practical application of our approach in examining documents customized from a database.

Blow flies (Diptera: Calliphoridae) can detect decomposing remains and begin colonizing the resource through oviposition soon after. The estimated time between colonization and insect evidence collection is referred to as the time of colonization (TOC). Forensic entomologists use the TOC to help estimate the minimum postmortem interval (mPMI), or the time between death and the discovery of remains. The presence of insecticides can influence blow fly behaviors, including oviposition. This study aimed to investigate how different concentrations of two insecticides, bifenthrin and clothianidin, affected blow fly oviposition both under laboratory and field conditions. In the laboratory experiments, Lucilia sericata (Meigen) and Phormia regina (Meigen) blow flies were exposed to beef liver treated with varying concentrations of bifenthrin or clothianidin. In the field, stillborn pig carcasses were treated with the same concentrations and time to oviposition was assessed and oviposition site preference observed. Insecticides have the potential to deter insect activity. Therefore, we hypothesized that insecticide exposure would result in delayed oviposition, altered site preferences, and increased mortality due to their modes of action. Statistical analyses indicated that the insecticides had no significant effects on the time to oviposition in the laboratory experiments, although species- and insecticide-specific effects were observed. Clothianidin, however, significantly affected mortality rates in both species. During field trials, bifenthrin significantly delayed oviposition, while clothianidin inhibited oviposition at the high concentration. These findings offer valuable insights for improving entomological evidence analysis in criminal investigations where insecticide exposure is suspected.

Immunolabeling based on fluorescence is a new technique that has been recently applied in the field of forensic science. In this paper, a new immunofluorescence method based on signal amplification was applied to develop fingermarks and improve the quality of pattern recognition with clear ridge details and high contrast. The high affinity between biotin and avidin and the one-to-many binding mode can connect several fluorescent groups together to achieve a signal amplification effect. The results indicated that the fluorescence intensity of the fingermark sample, as displayed by the biotin-avidin signal amplification system (BAS), was nearly three times higher than that revealed by previous immunolabeling methods based on fluorescence. Specifically, more fluorescent chromophores were bound to the friction ridges in BAS. Two proteins were selected as experimental target proteins for fingermark immunofluorescence visualization to optimize the visualization effect. The results showed that compared to keratin 1, dermcidin as the target protein in BAS achieved a more desirable effect, with 88.9% of the experimental samples left on nonporous objects having identification value. This method provides new insights for the development of fingermark spectra and is expected to become an effective and safe technology in the field of forensic science.

A piece of paper submitted as evidence can both have fingermarks with a high and low amount of sweat. When such paper is treated with 1,2-indanedione/zinc and subsequently heated at 160°C for 10 s, fingermarks with high sweat content may become overdeveloped. Attempts to prevent overdevelopment by reducing the heating time to <10 s were ineffective. However, it was found that maintaining the heating time at 10 s and reducing the temperature to below 160°C effectively prevented overdevelopment. In forensic practice involving latent fingermarks on actual evidence, an effective enhancement technique involves initially placing approximately 15 sheets of paper between the sample and an iron preheated to 160°C, and then applying heat for 10 s. This is subsequently followed by a secondary heating without the paper. This procedure has proven effective in enhancing fingermarks with both high and low sweat contents.

In recent years, there has been a significant increase in metal prices, particularly precious metals. Consequently, property crimes involving metal theft, including the theft of auto parts and catalytic converters, have also increased dramatically. The surge in catalytic converter thefts is linked to the use of precious metals, such as palladium, rhodium, and platinum, in their construction and their high price. A skilled thief can easily and quickly steal the catalytic converter by getting underneath the vehicle and, in a few moments, simply cut the exhaust pipes in front of and behind the catalytic converter using a common cutting tool, such as a reciprocating saw. Beyond the high price and the ease of committing the theft, police investigators experience difficulties finding forensic evidence that will incriminate the suspect. Furthermore, linking the cut items, such as the reciprocating saw, is not a simple challenge because of its mode of operation. The cyclic movement of the saw's blade, back and forth, removes a section of material. Therefore, examining a saw mark is mainly based on details relating to class characteristic features rather than individual characteristics. The authors seek to challenge this approach and demonstrate the feasibility of linking, using microscopic toolmarks comparison, cordless reciprocation saw, and the potential individual marks that may have resulted from the tip of its blade on the catalytic converter during the cutting action.

The house fly, Musca domestica, L. (Diptera: Muscidae), is a filth fly that is often associated with criminal and civil investigations surrounding abuse, neglect, and death of humans and other vertebrates. However, development data, which are crucial for determining the age of immatures collected under forensically relevant circumstances, are limited. Given the lack of data and the recognition of population-specific growth patterns, the aim of this study was to generate data for development of a M. domestica population from Texas, USA, on decomposing lean pork at 24.0°C (i.e., approximate room temperature in Texas) and 37.0°C (i.e., approximate human body temperature). As expected, fly development significantly differed between temperatures with development at the higher temperature taking significantly less time (development from egg to adult emergence occurred c. 48.5% faster at 37.0°C than at 24.0°C). The value of this dataset is demonstrated through an applied comparison with previously published data for the house fly. Differences in development times across life stages for the studies are evident, with shorter time of colonization estimations using the data published by Wang et al. (2018), especially in later life stages. These data represent the first development dataset for the house fly on decomposing flesh in North America. Furthermore, the comparison with the previously published dataset demonstrate data from this study are of value for future forensic investigations in Texas or possibly other parts of the United States where this species is encountered, as they can be used to determine time of colonization.