The synthesis of three β-substituted ninhydrin derivatives and their application to the development of latent fingerprints on paper surfaces were investigated. Under the same concentration, the effects of β-OMe, β-NO₂, β-Me ninhydrin were compared through latent fingerprint developments on different papers with multiple dimensions, respectively, and their effects were also compared with ninhydrin to analyze the advantages and disadvantages. Three β-substituted ninhydrin derivatives could develop fingerprints on different papers. The effect of β-NO₂ ninhydrin was slightly inferior to the others as its solution was brown at the same time the displayed fingerprint was dark brown; the effect of β-OMe, β-Me ninhydrin was equivalent to ninhydrin in many dimensions and the sensitivity was slightly higher than ninhydrin, as well as the stability of Ruhemann’s purple. The modification on β-position could change the fingerprint development effect of ninhydrin; the substitution of electron-donating groups could improve the fingerprint development effect of ninhydrin; the fluorescence performance of these compounds was not directly related to the visual effect of fingerprint display.

In this paper, the specific structures of two first-phase metabolites of 2-fluoro-deschloroketamine except nor-2-fluoro-deschloroketamine were determined, and a detection method of 2-fluoro-deschloroketamine, nor-2-fluoro- deschloroketamine, cis-Dihydro-2-fluoro-deschloroketamine and trans-Dihydro-2-fluoro-deschloroketamine in urine was estabished using HPLC-QQQ MS/MS. Through HPLC-HRMS screening, two metabolites of 2-fluoro-deschloroketamine, namely cis-Dihydro-2- fluoro-deschloroketamine and trans-Dihydro-2-fluoro-deschloroketamine were determined and then were synthesized specifically. The structures were identified by ¹H NMR, ¹³C NMR and 2D NOE NMR. The HPLC-QQQ MS/MS method for the detection of 2-fluoro-deschloroketamine, nor-2-fluoro-deschloroketamine, cis-Dihydro-2-fluoro- deschloroketamine and trans-Dihydro-2-fluoro-deschloroketamine in urine was established, which possesses a good linear relationship for 2-fluoro-deschloroketamine and its three main metabolites at the concentration range of 0.5~200 ng/mL, with the linear correlation coefficients all greater than 0.996 3, and the recoveries ranging from 81.60% to 119.33%. The quantitation of 2-fluoro-deschloroketamine and its three metabolites in actual urine samples was detected by the established method. This study determined the specific structures of two first-phase metabolites of 2-fluoro-deschloroketamine. The developed testing method has low detection limit, high recovery, and good reproducibility, which can be used in the qualitative and quantitative detection for the stable metabolites of 2-fluoro-deschloroketamine.

Objective and accurate forensic genetic analysis results are the basis for making accurate identification opinions. With the increasing sensitivity of testing equipment and amplification kits, the pressure to prevent laboratory pollution is increasing. Among them, the contamination of PCR amplification products is the most difficult type of pollution to prevent. This research introduces an anti-pollution amplification kit, which contains 16 short tandem repeats (STR) locus, one sex identification locus (Amel) and one Y chromosome insertion deletion locus (Indel). Anti-pollution amplification kit can obtain DNA fragment containing uracil base through STR multiplex amplification, and this type of DNA fragment can be efficiently hydrolyzed by uracil DNA glycosylase (UDG enzyme) at 50℃. An additional 50℃ incubation before each new round of PCR amplification can completely eliminate the pollution threat of previous amplification products to the results. After testing, the anti-pollution amplification kit has excellent anti-pollution ability, and uracil base does not change the DNA typing results. Its detection sensitivity does not decrease; the stability of DNA product fragments does not decrease; and subsequent electrophoresis analysis is not affected. This reagent kit can effectively eliminate contamination of amplification products.

Blood is a common physical trace evidence at crime scenes. In a fire scene, bloodstains and blood fingerprints are often two of the most important means of identifying a person and establishing the identity of a suspect. However, the fire scene, due to its exposure, destructiveness, and the invisibility of the causal relationship between the traces, poses difficulties and challenges for the recovery of relevant physical evidence and the investigation of the fire. Although fire destroys various traces of physical evidence left at the scene to a greater extent, bloodstains and blood fingerprints can be recognized and extracted by chemical recovery methods and soot removal techniques. This paper presents a comprehensive overview of the methodologies employed in the identification and analysis of bloodstains and blood fingerprints at fire scenes. It specifically concentrates on three core aspects: the alterations in blood composition within fire environments, chemical recovery methods, and techniques for soot removal in fire scenes. Considering the investigative requirements of public security organs in fire-related crime scenes, this paper summarizes the research progress and applications of detecting and analyzing bloodstains and blood fingerprints found at fire scenes, with the aim of providing a valuable reference for public security organs to investigate fire-related cases.

In the process of investigating telecommunication network fraud cases, especially in cases such as click farming, investment and financial management fraud and naked chat, APP and URL forensics analysis are the focus of network-side investigation. Because of the need to realize functions such as chatting, picture uploading and voice calling in the APP involved, the APP developed based on IM framework has become the mainstream, among which NetEase Yunxin IM is the most common third-party IM framework in the current fraud cases. However, as criminals continue to hide their means of committing crimes, for example, encrypting APPs or encrypting chat content end-to-end, direct analysis cannot obtain the key value of IM interface, or only the encrypted garbled code can be obtained, and chat content cannot be viewed. Based on this kind of cases, this paper introduces the principle of IM framework, the encryption technology and decryption method of APPs and chat content. Through in-depth reverse analysis and encryption algorithm analysis of this kind of APPs, the efficiency of clue mining and investigation and evidence collection of single fraud cases can be fully improved, which provides strong support for the detection of related cases.

In this article, the Raman spectrum inspection performance of six drug seizures at three different excitation wavelengths (532, 785, and 1 064 nm) is compared using Raman spectroscopy. Three to five distinctive scattering peaks in the Raman fingerprint area (100-1 800 cm^-1), with greater scattering intensity and no interference from typical adulterants, were chosen as the bass for the qualitative matching of the drug seizures when compared to the Raman spectra of the drug standards. It was discovered that in order to perform a Raman investigation of drug seizures, appropriate excitation wavelengths must be chosen based on the kind of drug involved. Additionally, if the drug seizures contain adulterated substances, the distinctive peaks of the pharmaceuticals that escape adulteration should be chosen for comparison. For seized heroin (HER), caffeine (CAF) and 3,4-methylenedioxymethamphetamine (MDMA), the near-infrared (NIR) excitation wavelengths of 785 nm and 1 064 nm are better than that of 532 nm for the Raman test, in which the 1 064 nm significantly reduces the background fluorescence of the HER seizure; for seized methamphetamine (MAMP) and ketamine (KET), the effect of the change of excitation wavelength was small, and the Raman response was good at three different excitation wavelengths, and the relative intensities of the Raman peaks in the fingerprint region and the functional group region (2 500 to 3 200 cm^-1) showed regular changes; for the Raman analysis of Magu, the excitation wavelength of 785 nm was superior, with a higher spatial resolution, which could observe more characteristic peak information while avoiding the fluorescence effect. This research work is based on Raman spectroscopy, which will provide a strong reference and basis for drug enforcement.

Artificial intelligence (AI) is a comprehensive new region developed by computer science, neuroscience, linguistics and other disciplines. It is an intelligent solution based on big data, machine learning and other technologies, which can improve morphological recognition ability, diagnostic efficiency and quality. With the rapid development of science and technology, AI technology has made great progress and been widely used, providing new solutions for solving various practical problems. “AI+” has been widely used in all walks of life and achieved excellent results, among which, a number of excellent research results have emerged in the field of forensic medicine. In recent years, forensic scholars at home and abroad have studied the application of AI technology in many aspects, such as postmortem interval estimation, diatom test, age and sex estimation, DNA map analysis, poison test and injury mechanism determination. The achievements have greatly promoted the progress of forensic science and demonstrated the advantages of applying AI technology to solve traditional forensic problems. This paper summarizes the literatures in recent three years, hoping to provide new ideas for the research of forensic pathology, clinic, anthropology and toxicology.

Synthetic cannabinoids are of hallucinogenic effect equivalent to or even stronger than that of cannabis, being listed under the first batch of new psychoactive substances controlled in China. There are many kinds of synthetic cannabinoids, among which MDMB-4en-PINACA and ADB-BUTINACA are recently the two ones of most active alkyl formyl indazole in the market. Such two synthetic cannabinoids have presumably not been reported about their metabolic researches in China. Thus, both the MDMB-4en-PINACA and ADB-BUTINACA were here probed into their metabolites from the blood and liver of rats. With 12 SD rats randomly divided into two equal groups: one for MDMB-4en-PINACA and the other for ADB-BUTINACA, each rat was fasted for 12 h and then intraperitoneally administered once by weight as per 1.0 mg/kg along with the two groups leaving one rat taken as the control that was not injected of drug yet executed just before administration. The remaining five rats in each group administered of drug were respectively killed at 5, 15, 30, 60 and 120 min after drug injection, having their blood and liver tissues received and successively analyzed into high performance liquid chromatography quadrupole time of flight mass spectrometry (HPLC-QTOF). The results showed that the experimental rats had MDMB-4en-PINACA metabolized into corresponding metabolites through double bond oxidative carboxylation, ester hydrolysis, 4-depentenylation and hydroxylation, with ADB-BUTINACA being metabolized through hydrolysis, 4-dealkylation, 4-butyl hydroxylation and hydroxylation. According to the response intensity of components in blood and liver tissue of rat, MDMB-4en-PINACA mainly converted into its metabolites from pentenyl oxidative hydroxylation (No. M6), pentenyl oxidative carboxylation (No. M7), methyl butyrate hydrolysis (No. M2) and further hydroxylation (No. M3/M4/M5) and dealkylation (No. M1), demonstrating its metabolic markers as M1 and M2. ADB-BUTINACA mainly turned into its metabolites from debutylation (No. A1), formamide hydrolysis (No. A2), butyl carboxylation (No. A3) and butyl hydroxylation (No. A4), with its metabolic markers being as A1 and A2.

In this paper, the characteristics of allele typing deletion of Y-STR loci and its correlation with AZF (azoospermia factor) deletion were discussed, which could provide reference for forensic practice. Y-STR kits (Yfiler Platinum, SureID PathFinder Plus) were used to analyze the blood samples of 23 461 male family members. A total of 14 cases with 4 or more Y-STR allele-dropout samples were found. Meanwhile, Sequence-tagged site (STS) was detected with Y chromosome microdeletion detection kit, and the deletion of AZF region of Y chromosome was evaluated according to the deletion STS. The results showed that the proportion of multiple Y-STR typing missing was 0.059 7% (14/23461), with 1 case of short arm and 13 cases of long arm, which were from different families with different types. STS deletion was detected in the AZF region in 13 long arm multiple typing deletion samples, and no abnormality was detected in 1 short arm multiple typing deletion sample. This study suggests that there is a correspondence between multiple STR allele dropouts in the long arm of Y chromosome and microdeletions in AZF region, and the biological basis of sterility exists in these typing individuals.

Vertebral artery injury (VAI), albeit relatively low of its incidence, is of high mortality. Vertebral artery is located in the transverse foramens, always unhurling complex structure under anatomy. Although VAI shows unobvious symptoms at the initial occurrence, its progressing paroxysm would yet lead to headache, vomiting, sensory disorder, inferior consciousness, and other neurological changes, even the fatal effect on final. Sometimes, VAI could be caused from the cervial surgery in clinical diagnosis and treatment, engendering an incident that forensic appraisal would be put up and/or of awareness. VAI can presumably turn up the blunt and/or penetrating injury, showing miscellaneous looks with direct injury, traction, torsion, sudden increase of intravascular pressure, and sometimes coexistence of multiple mechanisms. VAI can be analyzed of its resulting mechanism and progression through the examination of forensic autopsy and radiology into each segment of vertebral artery. VAI was here reviewed with purpose to improve the understanding about it and provide references for forensic peers.

New synthetic opioids are on the growing list of illicit drugs and pose a serious threat to human health. Some examples of NSOs include AP 237, piperidine, bromomorphine and a variety of 2-benzyl benzimidazole opiates. 2-benzyl benzimidazole opioids, also known as “Nitazenes”, many of which are regulated by the United Nations Commission on Narcotic Drugs, have become internationally prevalent in recent years. Metonitazene is an emerging potent synthetic opioid that first appeared in the recreational drug supply in mid-2020 and began to surge by the end of the decade, raising increasing public health concerns. In this study, we presented a method for the identification of a novel synthetic opioid metonitazene seized for the first time in China by gas chromatography-mass spectrometry (GC-MS) and ultra-high performance liquid chromatography-quadrupole/electrostatic field Orbitrap-MS (UPLC-Q- Exactive Orbitrap-MS). The unknown samples were extracted by methanol, and the supernatants were analyzed by GC-MS and UPLC-Q-Exactive Orbitrap-MS respectively. Isotonitazene was analyzed as a contrast. By GC-MS detection, the main characteristic ion peaks of the mass spectral fragments of unknown component with retention time of 15.167 min were m/z 86.1 (base peak), 58.05, 121.1, 205.05, 236.05 and 248.1. UPLC-Q-Exactive Orbitrap-MS detection showed that the excimer ion peak of unknown component with retention time of 7.35 min was m/z 383.207 7. The main ions of secondary mass spectrum were m/z 310.118 2, 264.125 2, 121.064 9, 100.112 1 and 72.080 8. Due to the lack of reference substance, the target was identified as metonitazene by retrieval of SWGDRUG and Cayman database, comparison of information in reported literatures and analysis of high-resolution mass spectrometry data. The method is simple, rapid and has good application prospect. It can be used in real case detection.

A method was developed for the determination of etomidate and its metabolite etomidate acid in hair and urine by high performance liquid chromatography-triple quadrupole tandem mass spectrometer (HPLC-MS/MS). The hair samples were ground and extracted by ultrasonic extraction with methanol. After protein was precipitated by acetonitrile, the urine samples were centrifuged at high speed and passed through 0.22 μm filter membrane, and then Agilent Eclipse Plus C18 RRHD (3.0 mm×150 mm×1.8 μm) column was used for analysis. Gradient elution was performed with 0.1% formic acid aqueous solution-acetonitrile as mobile phase at the flow rate of 0.5 mL/min. Electrospray ion source and multiple reaction monitoring (MRM) positive ion mode were selected. The results showed that the linear relationship of the two compounds exhibited good linearity in the concentration range of 0.5 to 50 ng/mL in urine and 0.025 to 2.5 ng/mg in hair, and the R² value was greater than 0.992 5. The extraction recoveries ranged from 91.0% to 107.5%, and the intra-day and inter-day precision RSD was 0.4% to 7.4%, while the intra-day and inter-day accuracy was 91.5% to 110.8%. In the actual cases, six hair samples and 4 urine samples were tested, and the test results showed that etomidate was detected in all six hair samples, and the metabolite etomidate acid was detected in two hair samples, but the concentration was much lower than the original. Etomidate and metabolite etomidate acid were detected in two urine samples, and the metabolite concentration was much higher than the original. In conclusion, this method can be used for rapid qualitative and quantitative analysis of etomidate and its metabolite in the hair and urine of etomidate users.

DNA analysis by capillary electrophoresis with fluorescent short tandem repeat (STR) detection plays a dominant role in DNA testing of various cases, but for difficult biological samples, such as highly corrosive and degraded bones, it is not effective due to the small number of motifs STR detected. This paper describes the application of second-generation sequencing technology in DNA testing of difficult biological samples such as highly degraded bones in forensic science practice. In a murder case that had remained unsolved for 30 years, the traditional STR testing method did not yield effective STR locus typing, but a complete autosomal locus typing was obtained by second-generation sequencing using the Precision ID GlobalFiler^TM NGS STR Panel v2 kit. However, through the second-generation sequencing method using Precision ID GlobalFiler^TM NGS STR Panel v2 kit, the genotypes of 31 autosomal loci were obtained, which helped the case unit to identify the source of the body and provided key technical support for the investigation of the case. By analyzing the advantages of NGS technology for such highly degradable samples and exploring the consistency between the STR locus typing results of CE electrophoresis detection and NGS typing results, it is shown that NGS technology can overcome the analysis limitations of CE for such highly degradable samples, supplement the shortcomings of CE technology, and provide new methods and technique for forensic DNA testing and analysis of difficult biological samples.

The composition of blood stains at the crime scene contains important information in many cases. Through the detection of blood components and the inference of the source of blood stains, it is helpful to the analysis and judgment of the nature of the case and the technical support of court proceedings. Based on the biological function of different tissues and the differences in biological metabolism, the stable endogenous small molecules in blood from different tissues can be an important basis for identifying the origin of blood tissues. In this paper, ultra-high performance liquid chromatography and mass spectrometry (UHPLC-MS) were used to analyze small molecule compounds. Through the pre-treatment of peripheral blood and menstrual blood samples, liquid separation and enrichment, and high resolution mass spectrometry, a variety of data analysis methods were integrated to screen out characteristic small molecules that distinguish peripheral blood and menstrual blood. Seven characteristic small molecules in peripheral blood and four characteristic small molecules in menstrual blood were identified combining with the human metabolome database (HMDB). The established UHPLC-MS method was applied to the detection of 10 blood samples, and the accurate identification results were obtained. Therefore, the method established in this paper can provide a new technical means for the identification of blood tissue sources in actual cases.

Currently, capillary electrophoresis-based Y-STR genotyping kits can detect up to 40 Y-STR loci simultaneously. However, these kits only report length-based genotypes and are unable to provide STR sequence information. The STRSeqTyperY68 kit, designed for forensic male pedigree differentiation using next-generation sequencing technology, excels at genotyping 67 Y-STR loci plus a sex-determinant locus in a single-tube reaction on the MiSeq FGx sequencing platform. It simultaneously provides both length and sequence polymorphism genetic information, simplifies testing procedures, enhances efficiency, and facilitates precise differentiation of male family lineages. The ITO method is commonly used to calculate the kinship index of two individuals’ biological relationship based on Mendel’s law of genetic segregation. Additionally, it evaluates consanguineous relationships within five degrees of kinship between two individuals. The combination of next-generation sequencing technology and the ITO method can effectively narrow down the range of potential families. This paper documents a rape and murder case that remained unsolved for eight years. By cooperatively utilizing the STRSeqTyperY68 kit and the ITO method, the potential connection between crime scene evidence and reference samples was evaluated. Gradually, the investigative leads were narrowed down, leading to the resolution of the case.

Differences in handwriting composition are crucial for recognizing the existence of alterations in questioned document examination. The ambient ionization mass spectrometry is increasingly being recognized for its utility in detecting ink changes, due to its benefits such as high speed, rich information, minimal destruction of the sample. In this paper, the desorption electrospray ionization mass spectrometry imaging (DESI-MSI), a prominent technique within ambient ionization mass spectrometry, was used to examine the suspicious handwriting to determine whether the document was altered. The authenticity of the number “1”, suspected of being added to change“2”into“12”, was scrutinized. The mass spectra of strokes of ink were obtained, and the suspicious“1”could differentiate from other numbers. Based on the MS data, the questioned part could be visualized through imaging, clearly demonstrating the evidence of tampering. Additionally, chemometrics were applied to cluster the handwriting composition data, aiding in the identification of the alteration fact. Compared with the traditional optical detection and spectroscopic method, DESI-MSI offered a more comprehensive analysis of the handwriting’s material properties, showcasing its potential for practical application. This technique provides an innovative perspective for examining such cases.

As soon as ChatGPT came out, it attracted widespread attention. This article takes ChatGPT as an example, briefly describes the use, characteristics and advantages of large language models, and analyzes the current controversies, ethical dilemmas and information security risks. This paper focuses on the analysis of the possible applications of large language models in crimes, and discusses the use of ChatGPT to assist in the acquisition of criminal skills, the implementation of cybercrimes, phishing attacks, and the dissemination of false information. This paper also explores the use of ChatGPT at the law enforcement fields, including serving crime fighting, crime prevention, law enforcement decision-making, and law enforcement capacity building. This paper believes that law enforcement agencies should keep an open attitude, pay close attention to the impact of the application of artificial intelligence technology on crime, represented by ChatGPT. Law enforcement agencies should strengthen research and deal with ChatGPT from both aspects of “positive” and “negative” attitude, applying new technologies to help with law enforcement activities and improve efficiency.

To solve the disputes on road rights caused by the invasion of traffic width by different traffic participants in the mixed traffic network, a method for measuring road surface distance in videos based on direct linear transformation theory is proposed. This method uses a one-dimensional direct linear transformation algorithm and relies on three characteristic points in the video that are collinear with the point to be measured to determine the direct linear transformation relationship between the image-side distance and the object-side distance, and then calculate the target distance. The measurement errors of this method are evaluated using the measurement values obtained from on-site scanning by Faro Focus^3D laser 3D scanner. Experimental results demonstrate that this method can effectively measure the road distance in videos, with a measurement accuracy reaching the centimeter level, and it is equally applicable to video images taken from different shooting angles. The application of this method can determine the traffic width of different parties involved in accidents in the mixed traffic network through video images, providing technical support for judicial appraisal and accident handling.

A 39 year old male victim was injured in the head, chest and abdomen by fist. Afterwards, his head was heavily hit against the wall and bed frame several times. During that time, he hit his right temples twice using a glass-made wine bottle. Then, he suddenly twitched and became unconscious. He was diagnosed with left frontotemporal parietal subdural hematoma, subarachnoid hemorrhage, cerebral hernia formation, and scalp contusion. The victim did not drink alcohol. After admission, an operation of removing bone flap decompression was performed to remove the left frontotemporal top subdural hematoma and repair the meninges. During the operation, dark red clot in the subdural area was found with the size of about 12 cm×13 cm, accompanying with contusion and laceration of left temporal lobe brain tissue. The victim remained in a coma for over 8 months after surgery. This article analyzes the mechanism of brain injury, the degree of participation of self-injury and intentional injuries, the identification of persistent vegetative state, and the evaluation of injury severity.

As one of the most commonly used reagents for amino acid detection, ninhydrin has a wide range of applications in forensic science and is a classic and effective method for displaying old fingerprints on permeable objects. However, the traditional ninhydrin display method still needs further improvement in the display effect of latent fingerprints on objects with complex background colors. Based on a review of relevant research results at home and abroad, a brief review was conducted on the composition of fingerprint substances, the mechanism of ninhydrin in fingerprint development, and the improvement of traditional ninhydrin development methods. A detailed review was also provided on the methods for enhancing the development effect since ninhydrin was applied in the field of fingerprint development. The innovation of the traditional ninhydrin solution method for enhancing visualization mainly manifests in three aspects: 1) optimization of ninhydrin solution method reagent formula, such as screening of the best solvent, exploring the optimal concentration, and discussing the influence of pH value on visualization effect; 2) The innovation of ninhydrin display methods, such as solid medium method, ninhydrin vacuum fumigation method, spray display method, etc., mainly solves the problems of carbonization interference and background ink interference in thermosensitive paper; 3) The fingerprint enhancement treatment using ninhydrin, mainly includes metal salt enhancement, rare earth-Ruhmann’s Purple violet coordination compound enhancement, and trypsin enhancement. The metal salt enhancement method and the rare earth-Ruhmann’s Purple coordination compound enhancement method have great research potential in the future development trend of latent fingerprints.

Identification of the cause of death is one of the essential tasks in forensic medicine. It is also the key for us to identify the nature of the case. An autopsy is a traditional method applied to find evidence of different causes of death. However, the traditional autopsy would damage the morphology of tissues and organs, affecting the morphological changes of injuries and diseases and leading to a bias in identifying the cause of death. Virtopsy is a novel technique developed in recent years. It is an amalgamation of forensic medicine and medical imaging. It has been known as a non-invasive autopsy method that uses imaging technology to obtain the surface and internal imaging information of the corpse to construct three-dimensional images of human organs and tissues, which provides imaging evidence to determine the cause of death, with the characteristics of non-invasiveness, objectivity, high efficiency, and storability. Virtopsy has been used to identify mechanical injury, traffic injury, asphyxia, disease, thermal injury, and so on. This paper reviews the application of virtopsy in identifying the cause of death and analyzes its advantages and disadvantages. We hope it will be the reference for forensic experts to determine the cause of death.

Objective and accurate assessment of visual impairment has been one of the challenging tasks in forensic identification. In forensic practice, visual impairments are commonly seen as caused by physical factors, but rarely by chemical factors such as methanol poisoning. Methanol and its metabolites can directly damage eye tissues and cause vascular paralysis and dilatation, damaging the nervous system. Visual impairment can appear after a few hours to 2~3 days of poisoning, manifesting as diplopia, blurred vision, and eyeball swelling and pain, followed by rapid vision loss and even blindness. Ophthalmologic examination reveals dilated and fixed pupils and diminished or absent light reflexes. Funduscopic examination reveals dilated veins, optic nerve papilla congestion, and edema, followed by pallor or optic nerve atrophy. Optic nerve damage rarely returns to normal completely. The mechanism of visual function impairment in methanol poisoning is mainly its metabolite formic acid or format, which is excreted very slowly in vivo and has a selective affinity for the eye’s neural tissues, inhibiting the oxidative phosphorylation process, affecting cellular respiration, and inhibiting ATP synthesis in mitochondria, leading to tissue toxicity and hypoxia and then degenerative changes of the cells, oligodendrocytes and astrocytes swelling myelin sheath loss, optic nerve edema and pressure on the optic nerve in the posterior sieve plate region, thus resulting in toxic optic neuropathy. Toxic optic neuropathy occurs when the optic nerve is compressed in the posterior region of the sieve plate, etc. Optic nerve atrophy often occurs after 1 to 2 months, and irreversible damage to the optic nerve and visual function can occur at a later stage. Two injury degree identification cases of visual impairment after methanol poisoning were reported. The methanol poisoning confirmation, the objective assessment of visual impairment, as well as the causal relationship between methanol poisoning and visual impairment, were discussed and comparatively analyzed, with a view to similar cases to provide a reference clue.

Detecting abnormal behavior is crucial for maintaining public security, especially in densely populated critical areas. Traditional target detection algorithms often struggle to deliver satisfactory results under these conditions due to challenges like dense target distribution, significant scale variation, and complex backgrounds. YOLOv8 is one of the better perforing detection models effect among the object detection models. This study introduces a novel approach to improve detection accuracy by integrating advanced mechanisms into the YOLOv8 backbone network. Firstly, the coordinate attention (CA) mechanism is incorporated into the C2f module of the backbone network. This enhances the network’s focus on targets amidst complex backgrounds by emphasizing relevant features and suppressing noise. Secondly, the swin transformer model is integrated into the YOLOv8 backbone. The swin transformer facilitates greater information interaction across the feature map, effectively utilizing the background information and improving object detection accuracy under complex scenarios. The datasets used in the experiments are described, the evaluation indexes of P, R, AP and mAP are listed, and ablation experiments and comparative experiments are carried out. Experiments demonstrate the feasibility and effectiveness of these improvements. The enhanced network is compared with several mainstream networks, showing a significant improvement in average accuracy, reaching 95.1%. Compared to the basic network YOLOv8, the average precision has been improved by 2.4%, which proves the effectiveness of this method. In summary, the innovative integration of the CA mechanism and Swin Transformer model into the YOLOv8 backbone network addresses key challenges in detecting abnormal behavior in densely populated and complex environments. These enhancements lead to improved detection accuracy, making it a promising approach for public security applications.

This paper explores the progress of artificial intelligence technology in the identification and reconstruction of crime scene elements. With the development of information technology, there are challenges faced by crime scene element identification and reconstruction. The paper discusses the application benefits of artificial intelligence, the relevant applications of artificial intelligence in forensic examination, and outlines the key steps of artificial intelligence in crime scene element identification and reconstruction, to explore the possibility of applying this method to crime scene element identification and reconstruction. Finally, the paper looks forward to the future development of artificial intelligence in forensic examination and suggests that it may play an important role in improving the intelligence level of crime scene examination and increasing the efficiency of case investigation. It is hoped that relevant research will provide a solution for the technical transformation of crime scene examiners and lay a foundation for the intelligent and digital development of forensic technology.

With the intensive integration of deep learning and computer vision, a series of advanced technologies such as facial recognition, image (video) generation, and image classification, have made rapid progress. However, deep learning models are considered “black box models” due to their difficulty in explaining internal processes and predicting results, which poses a serious challenge to the interpretability of image evidence in the field of forensic science. Based on this, this review outlines an overview of interpretability issues based on deep learning. Emphasis was placed on the theoretical and methodological research on the interpretability of facial features based on deep learning both domestically and internationally, such as saliency maps method, perturbation-based method, and score/statistics-based method. Their applications in facial recognition and other related fields, especially in the field of forensic science portraits, were summarized. This review proposes the problems of facial feature interpretability methods based on deep learning models, and looks forward to the future development direction of facial feature interpretability based on deep learning.

Calculation of the degree of lung compression by Mimics software remains the “gold standard”. In the forensic sphere, due to the complexity of the Mimics software, many people do not utilize this method in forensic practice. They may calculate degree of lung compression by visual observation, represent the result of degree of lung compression by some slicer of CT. These factors will lead to inaccuracies of calculated results. The aim of this study is to develop a model for automatic calculation of lung compression degree based on deep learning semantic segmentation technology, and explore the feasibility of deep learning for lung compression measurement by comparing the results of automatic calculations with Mimics software. In this study, 42 cases of the computed tomography (CT) data including pneumothorax diagnosis in DICOM format were collected each cases has about 350 images with a thickness of 1 mm. Among them, 32 cases used for training and 10 cases used for validation. The air-containing regions of 1943 images were manually annotated. An additional five chest CT cases were selected for external testing. The degree of lung compression was calculated by both the deep learning model and Mimics software, and the correlation between the results of the two methods and the calculation errors were analyzed. In the validation set, the average error between the deep learning model calculation results and the manual method was 2.4%, and the model processed an average of 356 per case with an average time of 60.04 s, while the average error in the test set was 4.4%. The aforementioned results lead to the following conclusions: The deep learning model constructed in this study has the potential to be applied in the automated measurement of the lung compression degree due to pneumothorax, which can provide a reference for the calculation of the lung compression degree due to pneumothorax in forensic practice.