The Sydney Declaration is an initiative led by an informal group of forensic scientists with diverse backgrounds. It offers a vision of forensic science based on the trace, as a vestige of a past event related to security or a possible law violation. An article published in Forensic Science International (FSI) introduces to this view [1]. Our investigation delves into how the forensic science literature has received this article (the SD article), nearly two years after its publication. One of the main challenges of this exploratory study was to define the appropriate scope of forensic scientific literature, within which the SD article must be located. In general, the publishing domain is quickly evolving, with many competing players, while still being structured around standard academic disciplines. The forensic literature, meanwhile, is scattered and poorly connected. This reflects the fragmentation of practice and research in forensic science, and the difficulty of situating a scientific activity in such a way as to bring out its forensic substance. Nonetheless, the SD article fills a gap. By deciphering the critical concept of trace, it highlights how pivotal forensic science is in addressing societal challenges. Scholarly literature expresses clear quantitative interest in the SD article. It has received significant qualitative citations on multiple levels and dimensions, in a highly relevant manner and in accordance with its aim of providing a forensic foundation for various debates that have been conducted separately, notably over the last fifteen years.

Forensic microbiology is a relatively new discipline, born in part thanks to the development of advanced methodologies for the detection, identification and characterization of microorganisms, and also in relation to the growing impact of infectious diseases of iatrogenic origin. Indeed, the increased application of medical practices, such as transplants, which require immunosuppressive treatments, and the growing demand for prosthetic installations, associated with an increasing threat of antimicrobial resistance, have led to a rise in the number of infections of iatrogenic origin, which entails important medico-legal issues. On the other hand, the possibility of detecting minimal amounts of microorganisms, even in the form of residual traces (e.g., their nucleic acids), and of obtaining gene and genomic sequences at contained costs, has made it possible to ask new questions of whether cases of death or illness might have a microbiological origin, with the possibility of also tracing the origin of the microorganisms involved and reconstructing the chain of contagion. In addition to the more obvious applications, such as those mentioned above related to the origin of iatrogenic infections, or to possible cases of infections not properly diagnosed and treated, a less obvious application of forensic microbiology concerns its use in cases of violence or violent death, where the characterization of the microorganisms can contribute to the reconstruction of the case. Finally, paleomicrobiology, e.g., the reconstruction and characterization of microorganisms in historical or even archaeological remnants, can be considered as a sister discipline of forensic microbiology. In this article, we will review these different aspects and applications of forensic microbiology.

The crystal violet (CV) staining technique represents a prevalent approach for the development of latent fingerprints, especially on adhesive tape surfaces. Nevertheless, the technique necessitates intricate formulations to augment its performance. In this investigation, an optimized CV staining protocol was developed, characterized by the absence of residual dye on the target substrates and the capability of facilitating fingerprint visualization under ambient light conditions. Four donors, comprising two males and two females, deposited natural fingerprints on various substrates, including glass microscope slides, aluminum foil, and 115 g glossy coated paper, without any specific guidelines. Fingerprints developed using cyanoacrylate fuming served as benchmarks and were contrasted with those generated through alternative methods: CV, ardrox, rhodamine 6G, powdering, and the optimized CV staining protocol. The fingerprint development experiment was replicated at seven distinct time intervals, encompassing 1 day, 1 week, 1, 3, 6, 9, and 12 months, resulting in a dataset of 420 fingerprints. The evaluation of fingerprint identifiability employed a scoring system established by the Home Office Centre for Applied Science and Technology. The results indicated that the optimized CV staining technique demonstrated superior performance, boasting a 92.9% rate of identifiable fingerprint development in contrast to other employed methodologies. Consequently, this optimized CV staining approach is recommended as an efficient, rapid, and straightforward critical dyeing method, applicable to a wide array of substrates in forensic investigations.

The present commentary reviews the considerations of the famous American criminalist Paul Kirk in his seminal publication of \'The Ontogeny of Criminalistics,\' written sixty years ago, regarding the status of forensic science and its fundamental principles. Professor Kirk aimed to examine forensic science as an independent scientific discipline, resulting in the identification of six key topics: 1) The need for fundamental principles; 2) the distinction between \'identification\' and \'individualization;\' 3) the qualifying elements of a profession; 4) the qualifying aspects of a science; 5) the need for a research-oriented basis; 6) the need for application of statistics and probability. In particular, Kirk deemed the nature of the progress made during his time as technical, practical, and transient at the cost of being fundamental, theoretical, and permanent. Predominantly, it is still the case today, with a post-effect fragmentation of forensic science into a myriad of ultra-specialized subdisciplines and applications. The lack of proper articulation of the most fundamental principles of forensic science was one of Kirk\'s most pressing concerns. The Sydney Declaration aimed to recapture the current fundamental (ontological and epistemological) status of forensic science, resulting in the redefinition of forensic science and its prime object of study, the trace, and in the consolidation of seven principles. The present commentary attempts to address Kirk\'s arguments in the Ontogeny in the context of the principles of the Declaration, with particular emphasis on the fundamental principles as well as Kirk\'s distinction between \'identification\' and \'individualization,\' which is considered critical to understanding the overall scope of forensic science.

A whole branch of theoretical statistics devotes itself to the analysis of clusters, the aim being to distinguish an apparent cluster arising randomly from one that is more likely to have been produced as a result of some systematic influence. There are many examples in medicine and some that involve both medicine and the legal field; criminal law in particular. Observed clusters or a series of cases in a given setting can set off alarm bells, the recent conviction of Lucy Letby in England being an example. It was an observed cluster, a series of deaths among neonates, that prompted the investigation of Letby. There have been other similar cases in the past and there will be similar cases in the future. Our purpose is not to reconsider any particular trial but, rather, to work with similar, indeed more extreme numbers of cases as a way to underline the statistical mistakes that can be made when attempting to make sense of the data. These notions are illustrated via a made-up case of 10 incidents where the anticipated count was only 2. The most common statistical analysis would associate a probability of less than 0.00005 with this outcome: A very rare event. However, a more careful analysis that avoids common pitfalls results in a probability close to 0.5, indicating that, given the circumstances, we were as likely to see 10 or more as we were to see less than 10.

Homicide perpetrators can use concrete as a means to conceal their victims. When concrete encasement is encountered in the forensic field, albeit rarely, it is often coupled with postmortem dismemberment. This method of obscuring the evidence presents unique investigative obstacles, specifically related to identification. Various approaches to obtaining fingerprints from decedents encased in concrete have been suggested and implemented over the years. The presented case is that of an initially unidentified 44-year-old male, who was subject to postmortem dismemberment and concrete encasement. Meticulous excavation techniques facilitated preservation of evidence and an anatomical reconstruction of the body. These techniques enabled inspection of the incision sites of the dismembered remains during the postmortem examination. Identifiable jewelry and tattoos were noted at autopsy. Further, the resulting concrete molds could be utilized to obtain fingerprints. These prints were used to ultimately identify the decedent.

The findings from a bloodstain pattern analysis (BPA) may assist in formulating or falsifying scenarios that are considered in the investigative stages of a criminal investigation. When a case proceeds to trial the bloodstain pattern expert may be asked about the relevance of their findings given scenarios that are proposed by the prosecution and defense counsel. Such opinions provided by an expert are highly relevant to police investigation or legal proceedings, but the reasoning behind the opinion or implicit assumptions made by the expert may not be transparent. A proper framework for the evaluation of forensic findings has been developed since the late twentieth century, based on the hierarchy of propositions, Bayesian reasoning and a model for case assessment and interpretation. This framework, when implemented in casework, mitigates some of the risks of cognitive biases, and makes the reasoning and scientific basis for the opinion transparent. This framework is broadly used across forensic science disciplines. In this paper we describe its application to the field of BPA using a case example from the Netherlands Forensic Institute (NFI).

Analysis of evidence is a challenge. Crime scene materials are complex, diverse, sometimes of an unknown nature. Forensic science provides the most critical applications for their examination. Chemical tests, analytical methods, and techniques to process the evidence must be carefully selected by the forensic scientist. Ideally, it may be interpreted, analyzed, and judged in the original context of the crime scene. In this sense, hyperspectral imaging (HSI) has been employed as an analytical tool that maintains the integrity of the samples/objects for multiple and sequential analysis and for counter-proof exams. This paper is an overview of forensic science trends for the application of HSI techniques in the last ten years (2011-2021). The examination of documents was the main area of exploration, followed by bloodstain analysis aging process; trace analysis of explosives and gunshot residue. Chemometric tools were also addressed since they are crucial to obtain the most important information from the samples. There are great challenges in applying HSI in forensic science, but there have been clear technological and scientific advances, and a solid foundation has been built for the use of HSI in real-life cases.

One of the tools for estimating shooting distance is examination of smokeless powder particle distribution on the target area. Components of the powder that are utilized for this purpose are nitrite anions. The traditional method for detecting nitrite anions mainly involves applying the Griess Test. A known-distance test firing is performed with shootings done at several distances from different targets. The color pattern corresponding to nitrite anions from the crime scene is then compared to the patterns obtained from known distances of the test firing. When a mutual shooting takes place at the crime scene, and a shooter also becomes a shootout victim, it is possible that when examining the shooter as a victim (i.e. target), additional nitrite-containing particles, resulting from his/her shooting, will be present on the shooter-victim clothing. This kind of addition may affect the estimation and practically give a shorter-distance estimation comparing to the actual distance. In this paper, an experimental setup was designed in order to understand if nitrite-containing particles were added to a victim as a consequence of him/her being also a shooter. All of the experiments were predominantly designed to try and minimize the effects of other influencing factors and variables in order to examine if the additions resulting from the firing action affect distance estimation. The experiments involved various types of pistols and distances. The results show that in such a scenario, there are marginal additions of nitrite signals on the victim\'s shirt. Although the forensic expert\'s final assessment was within the tolerance interval at all distances, caution should be exercised when attempting to estimate shooting distances in scenarios where the victim also shoots.

Shooting distances are utilized, among other forensic input, to position shooters and victims at the crime scene. Shooting distance estimation is done, mainly under the knowledge or assumption, that no intervening object has been present between the target and the muzzle. In the analysis of clothing items of victims that have been involved in a shootout, it is assumed that most of the marks and materials are left on the outer layers of clothing. The outer layers, not the inner layers, are the first objects the bullet meets. Consequently, undergarments are often disregarded for shooting distance estimation as they are not assumed to contain sufficient information in the form of marks or materials. In light of the above, it is the standard operating procedure in some forensic laboratories not to examine underwear. In this case report, the forensic examiners started by the implementation of standard operating procedures, thus examining only the outer layers of clothing of the victims. A thorough visual examination of the various clothing items led a forensic examiner to decide to extend the standard operating procedures, and try and examine an undergarment of one of the victims as well. The interpretation of examination products led to different scene reconstruction, one that may have led to a different interpretation of evidence. In this case, simply sticking to standard operating procedures might have led to less accurate crime scene reconstruction. This case report comes to stress the importance of thorough inspection of forensic exhibits, and scientific and critical thinking about different scenarios. Moreover, it demonstrates how the case-by-case approach in shooting distance estimation may add meaningful information, and eventually-bring us even closer to the truth.