Disputes over forensic appraisal errors are common in judicial practice. The fundamental cause lies in the unclear understanding of the nature of such errors, which in turn prevents accurate definition of forensic appraisal errors. This paper focuses on the core question of “What constitutes a forensic appraisal error?” and unfolds the discussion in three parts. First, by answering “What is an error?”, it establishes the premise for defining forensic appraisal errors. Second, through sorting out the objects of description and the essence of forensic appraisal errors, it clarifies the definition of such errors. Finally, it analyzes the contributing factors of forensic appraisal errors, including human factors, tool factors, evidence factors, and normative factors, thus identifying the causes of the errors. Clarifying the boundaries of forensic appraisal errors can promote the improvement of forensic appraisal legislation and the system for expert opinion admission. Meanwhile, it will facilitate the continuous optimization of forensic appraisal technical standards and quality control systems.

With respect to the scope of specialized issues of forensic appraisal, there are certain disputes or difficulties to be resolved in three aspects: legislative authorization, distribution of power, responsibility between forensic experts and judges, and actual conditions. In terms of legislative authorization, the legislation does not limit specialized issues of forensic appraisal to the “four major categories”, but affirms that “other categories” also belong to forensic appraisal. Therefore, the scope of specialized issues of forensic appraisal must be substantively judged. From the perspective of the distribution of powers and responsibilities between forensic experts and judges, specialized issues of forensic appraisal should include all issues about technical fact in a case that cannot be understood by ordinary people's senses or cannot be judged according to common sense, as well as issues about normative fact that are specially authorized by legislation or judicial interpretation, to be judged by social institutions or administrative agencies in litigation. On this basis, these factual issues must also have actual conditions for the implementation of forensic appraisal before they can be the object of appraisal; this requires that the implementation of forensic appraisal has both mature and reliable scientific and technological conditions and does not undermine litigation values such as substantive justice, due process, and litigation efficiency.

The illegal abuse of dextromethorphan, a widely used antitussive drug in clinical practice, has increasingly become an international issue. Currently, China has listed dextromethorphan in its national catalog of Category II Psychotropic Drugs and implements control measures in accordance with standards for narcotics regulation. Based on relevant literature, this study summarizes the metabolic pathways, abuse hazards, and control status of dextromethorphan, with a focus on the extraction and detection methods for dextromethorphan and its metabolites. It analyzes and discusses the applicability of these methods across different matrices, their qualitative and quantitative detection performance, and their multidimensional application scenarios in forensic appraisal. This study aims to provide a reference for the detection, identification, and abuse monitoring of dextromethorphan in the field of forensic appraisal.

The collection, recognition and identification of tool marks on skeletal trauma at crime scenes remain critical challenges in criminal investigation. As an important subset of tool marks, striated traces have garnered substantial attention due to their high prevalence in criminal activities. This paper reviews the current research status regarding methods for collecting and identifying striated traces resulting from skeletal trauma. Firstly, it delineates the application status and limitations of two-dimensional (2D) and three-dimensional (3D) acquisition technologies within this domain. Subsequently, it systematically evaluates recognition techniques for striated traces based on algorithms and deep learning, with a specific focus on the applicable objects and scope of image recognition technology. Finally, based on existing research, this paper provides a summary and prospects for future research directions.

Objective To examine the effects of different answering modes on the galvanic skin response (GSR) in the concealed information test (CIT). Methods A total of 150 participants were recruited and randomly assigned to different experimental conditions according to the experimental design. The GSR of each participant was scored using the Lykken scoring method. The accuracies of the GSR for both perpetrators and innocent participants were analyzed under the three answering modes in the CIT: silence, honest answer, and deceptive answer. Results The accuracies of identifying perpetrators under the answering modes of silence, honest answer, and deceptive answer were 53.3%, 33.3%, and 86.7%, respectively. The accuracies of identifying innocent participants under the answering modes of silence and honest answer were 100% and 93.3%, respectively. Conclusion Answering modes have a certain influence on the GSR in the CIT, which can provide a reference for the standardized application and criteria development of polygraph testing technology.

Objective The application of analysis of geological materials like rocks in forensic science is growing. It is of great significance to adopt multi-techniques for joint analysis. Methods This study employed X-ray diffraction (XRD) combined with Rietveld full spectrum fitting quantification, polarized light microscope (PLM), X-ray fluorescence spectrometry (XRF), and scanning electron microscope-energy dispersive spectrometry (SEM-EDS). These techniques were used to investigate the mineral and element composition of rock samples from crime scenes and suspects’ residence. Results The study identified calcite altered by dolomitization, quartz, and illite in two samples. The main elements detected included magnesium, aluminum, silicon, phosphorus, sulfur, potassium, calcium, iron, and strontium. In the correlation calculation, the semi-quantitative data of minerals, oxides, and elements from two samples were set as index values, and the correlation coefficient between the samples was calculated .The coefficients were 0.999 by using the cosine of the angle and 0.965 by the Spearman’s rank correlation coefficient method. Conclusion The results suggested a probable common origin for the two rock samples. This study provides valuable tools and technical support for identifying geological materials such as rock, ore and solid waste in criminal investigation.

By sorting out the triple logic underpinning the substantiation process of cross-examining civil appraisal opinions since 1979, we find that the first dimension has achieved a cognitive shift from conclusion to opinion, yet still tends to examine appraisal opinions from a static, results-oriented perspective. In the second dimension, appraisers’ court appearances have yielded notable effects, but the relevant rules remain overly broad; while the system allowing expert assistants to appear in court has been established, their litigation status remains controversial, with a mismatch between rights protection and role positioning. As for the third dimension, judges’ participation in cross-examination is mired in a dilemma of ambiguous role orientation and inadequate professional competence, which blocks the path connecting cross-examination to the formation of judicial conviction. In view of the above, the substantiation of cross-examination for civil appraisal opinions in China should be based on the binary framework of expert confrontation. First, it is imperative to dynamically grasp the entire generation process of appraisal opinions from a life-cycle perspective. Second, guided by the principle of equal confrontation, we should refine the rules governing appraisers’ court appearance, clarify the scientific position of expert assistants, and establish a right protection mechanism for them to obtain information throughout the judicial authentication process in light of their role as technical representatives. Third, efforts should be made to enhance judges’ cross-examination capabilities, thereby smoothing the path from cross-examination to judicial conviction and enabling a more effective response to modern litigation.

By combination of quantitative evidence support and the five-level propositional framework, the Bayesian Likelihood Ratio model is considered to be the mainstream international scientific evidence evaluation paradigm. In China, the application of Bayesian Likelihood Ratio model in the evaluation of DNA evidence is facing a triple challenge: At the technical level, there are problems such as difficulties in the separation of mixed samples, allele dropout, and model uncertainty; At the institutional level, the current normative documents regard uncertainty as a technical flaw, forcing appraisers to issue “pseudo-certainty” conclusions; At the cognitive level, the fact finder is prone to fall into “numerical absolutes” due to the lack of statistical knowledge; At the institutional level, the current regulatory documents regard uncertainty opinions as technical defects, forcing experts to issue “pseudo-certainty” conclusions; At the cognitive level, the fact-finder is prone to fall into “numerical absolutism” due to lack of statistical knowledge. Based on this, the study proposes a multi-dimensional improvement path: developing high-precision algorithms and optimizing mixed-sample analysis, constructing dynamic genetic databases to reduce model bias, revising judicial norms to recognize the reasonableness of uncertainty expression, and establishing a hierarchical review standard for “technical uncertainty” and “cognitive uncertainty”. The aim is to improve the practical application value of DNA evidence and promote the accuracy and fairness of scientific evidence evaluation in court.

The scientificity, logicality, and rationality of the forensic appraisal documents are not only the focus of the People’s Courts’ review, but also the focus of the courts’ cross-examination. Through the writing of the forensic appraisal documents and their existing problems, the specific connotation of the scientificity, logicality, and rationality of the forensic appraisal documents is elaborated in detail, focusing on the standard and method of proof of litigation evidence, the basic requirements and forms of logical reasoning and logical argumentation, the identification of objective information and the reliability test method of the laboratory examination results, etc., to ensure the validity of the appraisal opinions as litigation evidence. It is also recommended to formulate the Specifications for the Preparation of Forensic Appraisal Documents and the Standards for the Quality Evaluation of Forensic Appraisal Documents, and to carry out professional training such as jurisprudence and logic for forensic appraisers, so as to improve the professional knowledge and practical ability of forensic appraisers. 

Medical imaging data serves as pivotal evidentiary material in forensic clinical identification, and the integrity and clarity of such data are critical for accurate injury assessment. The acquisition of medical imaging information primarily relies on the imaging equipment and systems of medical institutions. Incomplete, unclear, and difficult-to-access imaging data has long been a challenge for forensic appraisers in practice. With the continuous advancement of cloud imaging technology, regional medical imaging centers have been established in more regions, achieving groundbreaking progress in cross-institutional sharing of imaging data. This study explored the application value of cloud imaging technology in forensic clinical identification based on the current development status of cloud imaging technology and the practical experience of cross-institutional regional sharing on Jiangsu Province Cloud Imaging Platform. Additionally, it proposed ideas and recommendations for appraisal institutions to access cloud imaging platforms and construct a new medical-appraisal collaborative model.

As the core engine driving high-quality economic development, new quality productive forces empower the intelligent transformation of the forensic appraisal field. The Fourth Plenary Session of the 20th Central Committee of the Communist Party of China and the “Recommendations of the Central Committee of the Communist Party of China for Formulating the 15th Five-Year Plan for National Economic and Social Development” have made explicit arrangements for developing new quality productive forces, providing policy guidance for their integration with the forensic appraisal field. This study deconstructs the core connotation of new quality productive forces, analyzes their coupled and symbiotic relationship with the forensic appraisal field, and identifies current obstacles hindering their full release, including the absence of legal regulations for intelligent appraisal, data leakage risks, deepfake issues, algorithmic black box dilemmas, and the shortage of new-type appraisal professionals. To address these challenges, this study proposes the following measures: formulating a unified Forensic Appraisal Law incorporating intelligent elements; establishing a hierarchical and categorized data access and blockchain-based evidence preservation mechanism; strengthening the obligation to label AI-generated appraisal results to address deepfake issues; creating an algorithm transparency and accountability mechanism; and cultivating interdisciplinary professionals with both appraisal expertise and intelligent technology skills through industry-academia-research integration. These measures aim to provide institutional support for the paradigm shift in forensic appraisal and promote high-quality development in China’s forensic appraisal field.

In vehicle fire incidents, oil leakage is a common cause of fire. Accurately determining the ignition mechanisms of such fires is crucial for investigating and identifying the cause of fire. Based on a real vehicle fire case, this study confirmed that engine oil leakage was the cause of fire by analyzing video recordings of the combustion process, examining combustion traces on the vehicle, integrating the results of trace evidence identification, and validating the findings through simulation experiments. During the research process, the distribution patterns of engine oil after leakage, temperature field distribution, ignition conditions, and flame propagation paths within the engine compartment were systematically investigated, revealing the characteristic development mode of such fires. The results showed that when leaked engine oil came into contact with a high-temperature exhaust pipe, it formed a characteristic oil film and rapidly vaporized. Upon meeting the ignition conditions, a typical deflagration phenomenon occurred, followed by rapid spread along the paths of combustible materials. These characteristics, manifested as unique fire traces and combustion trajectories, can serve as important criteria for determining the cause of vehicle fires. The findings provide scientific theoretical support and practical technical references for the investigation and identification of vehicle fires caused by oil leakage.