Forensic appraisal services in legal aid cases can be referred to as forensic appraisal public welfare services. In China, the overall promotion of top-level design and the innovation while maintaining integrity in local exploration have jointly outlined the basic institutional framework of forensic appraisal public welfare services. However, this service also presents problems such as low legislative level, significant differences among regions regarding regulatory content, and rough operating procedures. Forensic appraisal public welfare services not only have the tool value of ascertaining case facts and achieving substantive justice, but also have the inherent value of promoting the balance of power between the two parties, promoting human rights judicial protection, and improving litigation efficiency. In the future, it is necessary to strengthen the systematic construction of forensic appraisal public welfare services, taking national responsibility, due process, and litigation efficiency as the basic principles thereof, adopting the legislative model of incorporating forensic appraisal public welfare services as a whole into the Legal Aid Law, and improving specific designs from the aspects of service provider, service scope, operating procedures, guarantee of funds, and digital construction.

The integration of appraisal and mediation refers to the integration of pre-litigation appraisal and pre-litigation mediation. The development of integration of appraisal and mediation is an innovative attempt to adhere to and develop the “Fengqiao Experience” in the new era, and it should follow the principles of consensus, suitability and integration. Various regions have carried out diversified explorations in the field of integration of appraisal and mediation, laying a good foundation for the system improvement of the the procedures of integration. The implementation of the Supreme People’s Court’s Working Regulations on Entrusted Appraisal in Pre-litigation Mediation （Trial Implementation） has played an important role in integrating public legal service resources and promoting the construction of the public legal service system. The specific presentation of the integration of appraisal and mediation in the litigation process can be directly observed in some effective judgment documents. The relevant facts, evidence and law application have been clearly expressed in the parties’ submissions, the focus of disputes, the reasoning of the judgment and other parts of such effective judgment documents. In response to the practical needs of the integrated development, and aiming at the existing problems in the development of the integration, such as the unclear basic positioning, the unclear conditions and functions, the insufficient synergy of procedures, and the imperfect evaluation mechanism, it is proposed to formulate a special judicial interpretation on the integration, to clarify the basic positioning of the leading role of people’s courts  and the judicial administrative organs’ participation, to integrate the main functions and double review conditions of the legal service entities, to standardize series procedures of the integration, and to precisely design the evaluation mechanism for the integration.

Objective To study the distribution of five hypnotics (diazepam, zolpidem, et al) and metformin in the hair samples of users, providing reference for characterizing the medication history. Methods The hair samples were segmented along the growth direction, ground and extracted. The content in each hair segment was determined by liquid chromatography-tandem mass spectrometry (LC-MS/MS) and analyzed with the donors’ medication information. Results The distribution range of diazepam, alprazolam, clonazepam, and metformin in the hair samples corresponded to the duration of medication. The contents of analytes were related to multiple factors such as physical and chemical properties of the drugs, dosage, hair color, and individual metabolic differences. Conclusion The segmental hair analysis and drug distribution characteristics of real users can provide basic data support for the characterization of donors’ medication history in case investigation.

Objective To develop a high-efficiency and sensitive analytical method for detecting volatile organic compounds (VOCs) on human skin surfaces, aiming to support suspect profiling in the field of forensic science. Methods A fully automated headspace-solid-phase microextraction-Arrow (HS-SPME-Arrow) system coupled with gas chromatography-mass spectrometry (GC-MS) was implemented. Optimized extraction conditions included：use of a 50 μm/30 μm DVB/CWR/PDMS extraction fiber membrane, 25-min incubation, 25-min extraction at 60 ℃, and 3-min desorption. Comparative studies with conventional SPME was conducted to evaluated the methodological enhancements. Results The extraction efficiency of the SPME-Arrow method was 1.6-fold higher than that of conventional SPME method, showing significant advantages in terms of automation capability and adsorption capacity. Nine gender-specific VOCs biomarkers were successfully identified, and the accuracy rate for gender prediction using this biomarker combination reached 93.3%. Conclusion This VOCs profiling method exhibits high efficiency and sensitivity, providing a novel forensic tool for suspect characterization with significant investigative potential.

Objective To identify and screen characteristic volatile components in human hand and foot odors associated with gender and age, thereby characterizing the attributes of different population groups. Methods Thermal desorption-gas chromatography-mass spectrometry (TD-GC-MS) was used to analyze the volatile compounds from human hands and feet. Single-factor and multi-factor analyses were used to identify different components related to gender and age across various populations. Genetic algorithm-random forest (GA-RF) machine learning techniques were used to predict the characteristic components of different genders and ages, and to construct a classification model. Results A total of 304 volatile components were identified from human hand and foot odors. They were discerned through t-tests and orthogonal partial least squares-discriminant analysis (OPLS-DA). Components with P<0.05 and VIP>1 were selected. Genetic algorithm (GA) was used to optimize random forest (RF) to construct a judgment model. The accuracies of gender identification using hand and foot features were 92.02% and 81.46%, respectively, and those for age identification were 76.13% and 73.49%, respectively. Conclusion Based on statistics and GA-RF machine learning methods, gender and age difference markers in human hand and foot odor were screened, and a prediction model was constructed, providing a novel approach for the biometric characterization of human odor in forensic science.

Objective This study aims to evaluate the performance of a self-developed electronic nose under different experimental conditions and explore its application in human odor recognition, particularly for gender classification using convolutional neural network (CNN) algorithms. Methods Firstly, the performance of the electronic nose was evaluated using acetone, ethanol, and isoprene as target gases with a concentration of 2×10⁻⁶ mol/m³, under gas flow rates ranging from 500 to 2 500 mL/min. Multiple factors, including flow rate, enrichment time, storage medium, and storage time, were considered in the experiments. Secondly, odor samples were collected from 25 male and 25 female participants, and gender classification of the gas samples was performed using feature data obtained from the electronic nose, combined with a CNN algorithm. Results The electronic nose performed best at gas flow rates of 1 500-2 000 mL/min. The use of aluminum foil bags resulted in minimal gas attenuation and better preservation. The optimal enrichment time for detection was 10 minutes. The gender classification accuracy based on hand and foot odors was as follows: left hand 96.55%, right hand 93.10%, left foot 100%, and right foot 96.55%. Conclusion This study demonstrates that optimizing experimental conditions significantly improves the performance of the electronic nose. Furthermore, the integration of CNN algorithms proves effective in human odor recognition, achieving high classification accuracy and providing a feasible solution for practical application of electronic noses in human odor analysis.

 In promoting the construction of the forensic appraisal aid system with the characteristics of public welfare, the key problem is to clarify the responsible subjects and distinguish the responsibility of different subjects. Through the analysis of China’s forensic appraisal aid practice, three main aid models are identified: the “pure institutional model”, the “state-institution integration model” and the “state, institution and individual co-participation model”. At the same time, it is found that there are three pairs of contradictions in the distribution of the responsibilities of forensic appraisal aid, which are the contradiction between the unlimited liability and the limited liability of the state, the contradiction between the pursuit of profit and the performance of public welfare by the appraisal organization, and the contradiction regarding whether the applicant has liability or not. In view of this, this article, from the legal and moral dimensions, expounds on the necessity for the state, institutions and aid applicants to serve as accountable  entity forensic appraisal aid. On the basis of fully considering China’s national conditions, in the field of forensic appraisal aid, the author puts forward the optimal responsibility distribution model: The state should firmly shoulder the responsibility, the forensic appraisal institutions should actively take on the “feasible” obligations, and the applicants should be required to bear a reasonable burden, and the social forces should be steered to gradually participate in the field of forensic appraisal aid, aiming to build a stable, efficient and sustainable forensic appraisal aid system. 

Bayesian statistical reasoning, based on prior knowledge and evidence information, conducts logical reasoning and probability estimation of the possibility of an event. It has developed not only internationally into a standard logical framework for the evaluation of forensic evidence, but also its likelihood rate model helps to make the formation of a judge's inner conviction explicit, standardized, and scientific, which is of great significance for preventing judges from abusing their discretionary power. In recent years, although the academic community in China has gradually increased its introduction and research on this type of statistical evidence or reasoning method, there seems to be an attitude of avoidance towards this type of evidence in judicial practice, and there is also a lack of relevant research. In contrast, although Britain is cautious about Bayesian statistical evidence, it has worked out a set of effective rules through trial and error in practice. Based on the current situations, we should try to promote the research by multiple occupational groups from different perspectives, and strive to reach a consensus on the application of Bayesian statistical evidence as soon as possible.

At present, there is a phenomenon of “dualization” in medical damage appraisal. The main body of medical damage appraisal includes the medical associations and judicial appraisal institutions. In the practice of appraisal, the client often requires an appraisal body to quantify the consequences of personal injury to patients who are still alive.  The commonly used quantitative method in practice is disability rating. However, in the practice of medical damage appraisal, the applicable standards for disability rating are not uniform.The disability grades may be inconsistent, which is easy to cause confusion and disputes, and is not conducive to the proper handling of medical injury cases. This paper will start from the problems existing in the quantitative assessment of the damage consequences conducted by medical associations and judicial appraisal institutions in medical damage appraisal cases, discuss the subject of disability assessment of damage consequences and the application of standards, and hope to provide unified and standard reference opinions for solving the problem of medical damage compensation, promote the smooth progress of litigation, and help efficiently resolve disputes between doctors and patients.

In China, there are still cognitive biases on non-determinative handwriting apppraisal opinions, including negating their scientific integrity, attributing insufficient professional competence to the appraisers, and locating the reference function of the opinion, which leads to multifaceted conflicts, mostly between appraisal standards and judicial rules and those of perception within the judiciary. The causes of these biases stem from both misconceptions about the appraisers themselves and resistance to the inherent nature of non-determinative opinions. Some foreign countries have initially constructed handwriting opinion expression systems based on the logical basis of non-certainty, and they have also experienced the understanding of the differences that we face today. By analyzing the construction process of their handwriting opinion expression systems, we can get reference to develop a more scientific handwriting opinion expression system.Based on the above analyses, this paper proposes to adjust the expression system of handwriting opinions to adapt to reality in our country, focusing on clarifying the status of evidence, adjusting the elements of the expert opinions, and improving the technical standards, through the integration of technical and legal perspectives.