Currently,2-fluorodeschloroketamine(2F-DCK),an analog of ketamine(KET),is considered one of the emerging new psychoactive substances(NPS).Its abuse is on the rise globally due to its structural and anesthetic similarities to KET.The pharmacological properties of KET have been extensively studied,but reports on the pharmacology of 2F-DCK and its metabolites are scarce.In the study,we focused on the pharmacokinetics of 2F-DCK and its phase I metabolite nor-2F-DCK in rodent model.Our aim was to analyse changes in their metabolic profiles over time and to construct a predictive model based on the concentration ratio of 2F-DCK to its metabolite for estimating the last 2F-DCK administration time.Eighteen healthy Sprague-Dawley(SD)male rats were randomly divided into three groups:high-and low-dose 2F-DCK groups and a control group(n = 6).Whole blood was collected from the inner canthal vein at different time intervals after oral gavage.The blood samples were extracted via liquid-liquid extraction and analysed by high-performance liquid chromatography-tandem mass spectrometry(HPLC-MS/MS)in a positive ion mode using multi-reaction monitoring.Mean blood concentration-time curves showed that 2F-DCK was undetectable at 8 h post-administration,whereas nor-2F-DCK was still detectable at 12 h(low-dose group),demonstrating that nor-2F-DCK could be used as a reliable biomarker for 2F-DCK identification.Pharmacokinetic parameters were calculated by a pharmacokinetic software DAS 3.2.8,employing a non-compartment model.The results showed the elimination half-lives of 2F-DCK are 0.20 h(low-dose group)and 1.07 h(high-dose group);while those of nor-2F-DCK were 1.51 h(low-dose group)and 5.01 h(high-dose group),respectively.The time of maximum concentration(Tmax)of 2F-DCK in low-dose group was same as that in high-dose group(0.25 h),and the Tmax of nor-2F-DCK in both groups was 1.00 h,which indicated that the Tmax was dose-independent.Significantly,the best predictive model was obtained from the relationship between the concentration ratio of 2F-DCK to nor-2F-DCK and the administration time of 2F-DCK,exhibiting considerable potential for application in clinical drug monitoring and forensic illegal drug identification.
For disaster victim identification(DVI),the destruction of human remains can pose significant challenges in discerning useful identifying details.In such cases,dental age estimation may help to identify individuals,but tends to be less accurate for adults than for younger victims with less mature dentition.The Kvaal and Cameriere methods are used to estimate adult age by radiologically assessing pulp reduction resulting from the secondary dentin deposition in single-rooted teeth.This review aims to provide a meta-analysis of recent studies and their accuracy using Kvaal and Cameriere methods for adult age estimation from radiological pulp assessment.Searches were conducted in databases including Scielo,PubMed,EBSCO,Scopus,ScienceDirect,and Wiley Online Library.The searches were performed using the guidelines of Preferred Reporting Items for Systematic Reviews and Meta-Analyses(PRISMA).The search resulted in 1 241 studies of which 39 studies were eligible to be included.These studies comprised data from 12 distinct populations with a total of 7 510 samples.The Kvaal method underestimated(-2.95 years,95%CI)and the Cameriere method overestimated(0.89 years,95%CI)the assessed adult age in this meta-analysis.The Cameriere method presented lower mean difference and standard error of the estimation(SEE)compared to the Kvaal method.Overall,both methods can be used as adjunctive methods to estimate adult age through population-specific equations.
The identification of biological fluids is crucial in forensic biological investigations,particularly in cases involving sexual crimes.In such cases,semen is the most frequently analyzed biological sample,serving as critical forensic evidence.It can confirm sexual contact and help identify perpetrators through genetic analysis.Regarding semen detection,preliminary tests are classified into two types:presumptive and confirmatory.These tests are used to detect and confirm the presence of semen,respectively,helping to corroborate a victim's account,identify a suspect,and provide compelling forensic evidence in court.Findings from forensic biological investigations are essential to judicial decision-making.Technological advancements have driven the development of new methodologies to improve the sensitivity,specificity,and effectiveness of semen detection.These innovations contribute to faster and more efficient criminal investigations,paving the way for a future where traditional methods will be complemented by more sophisticated approaches.As these technologies continue to evolve,it is expected that traditional methods will be integrated with modern techniques,resulting in quicker and more accurate criminal investigations.This review aims to highlight the importance of preliminary tests of semen detection in the context of forensic biological investigations of sexual crimes;describe the different preliminary tests used for semen detection in forensic samples;differentiate between the legal frameworks of presumptive and confirmatory tests;demonstrate the historical evolution and current relevance of semen detection tests;present new technologies and emerging methods for semen detection;and promote critical thinking about the use of preliminary tests in forensic biological investigations of sexual crimes,considering their limitations and implications for forensic practice.
Diffusion models have emerged as powerful generative tools.Recently,numerous image watermarking techniques have been developed to ensure copyright protection and content traceability.These techniques also play a vital role in multimedia forensics,where digital watermarks are used to verify authenticity,detect tampering,and support legal attribution.Conventional watermark removal techniques operate at the image level,employing various post-processing strategies to degrade embedded watermarks.However,these methods often incur substantial computational costs,limiting their practical applicability.In this work,we propose a novel watermark removal approach targeting the diffusion model itself,specifically focusing on fine-tuning the Variational Autoencoder(VAE)decoder.Utilising Low-Rank Adaptation(LoRA),we efficiently optimise a subset of parameters to suppress watermark signals while preserving image fidelity.An adversarial classifier is incorporated to guide the training process,ensuring effective watermark removal.Furthermore,perceptual and structural similarity losses are integrated to mitigate degradation in image quality.Experimental results show that our approach effectively eliminates embedded watermarks,providing a robust and lightweight solution for watermark removal in diffusion-based generative models.This work also provides a technical perspective for analysing the reliability and resilience of watermark-based mechanisms in generative AI systems,offering insight into their potential limitations in forensic identification.
Radiographic identification is currently making an important contribution to forensic anthropology. Several studies have reported that evaluating the maxillary sinus (MS) and the frontal sinus (FS) can be an effective technique for estimating sex. However, there is a lack of data on these measures for modern inhabitants of North Africa, so population-specific norms must be established. This study aims to analyse the correlation between sex and MS and FS measurements in a contemporary Tunisian population using multi-slice computed tomography (MSCT). The study involves a retrospective data collection of 354 cranial MSCTs from 188 men and 166 women. The ASiR TM software was used to create 28 landmarks and measure 24 distances as well as eight volumes. In this study, 15 measurements were proposed for the first time, including seven distances and eight volumes. The data were analysed using univariate analysis and logistic regression to create and validate a discriminant equation. The results showed that males had higher mean values of the MS and FS (P<0.05). A six-variable model was able to accurately predict sex with a sensitivity of 77.9%, a specificity of 75.6%, and an accuracy of 76.8%, with a sex bias of -4%. The MS was a better predictor of sex than the FS (accuracy of 70.1% and 65.5%, respectively). The highest accuracy was associated with the minimum inter-maxillary sinus distance. The findings indicate that MS and FS MSCT measurements are highly dimorphic and can provide an accurate alternative for sex estimation in contemporary North African individuals. Key Points center dot Contribution of radiographic identification to forensic anthropology. center dot CT scan measurement of maxilla-frontal sinuses with 24 distances and eight volumes. center dot Measurements of maxilla-frontal sinuses are highly dimorphic. center dot Design a discriminant equation with an accuracy of 76.8%, and a sex bias of-4%.
The identification of weapons involved in aggravated assaults with bladed weapons,as well as the correlation between bodily injuries and the energy required to produce them,is crucial for accurate prosecution.In murder cases involving knives,crime weapons often leave marks on bones.Therefore,differentiating the marks created by various weapons and understanding the energy involved in the assaults are essential for forensic investigations.This technical note presents a drop test device designed to deliver controlled impacts at specified energy levels.The device allows for the attachment of different weapons and ensures high accuracy in energy delivery,enabling the consistent reproduction of similar stab marks.Additionally,it can be used with various types of weapons,including blunt and sharp tip ones.The functionality of the device was demonstrated through rib stabbing experiments.Different marks were created using two energy levels and two similar weapons to analyse their effects on the resulting stab marks.The drop test device provides a systematic approach for studying stab marks by enabling controlled and repeatable experiments on different materials or tissues.Its ability to replicate injury patterns under controlled conditions offers valuable insights for forensic investigations.
Accurate estimation of the postmortem interval(PMI)can be crucial for forensic investigations.Recent advances in molecular biology have highlighted postmortem alterations in RNA expression as promising biomarkers for PMI determination.However,previous studies have been constrained by using limited types of transcripts and low-throughput quantification methods,restricting their forensic utility.In this study,we systematically characterised time-dependent transcriptomic changes in rat brain tissue using RNA sequencing(RNA-seq),with a focus on protein-coding mRNAs,circular RNAs(circRNAs),and two major classes of non-coding RNAs:long non-coding RNAs(lncRNAs)and microRNAs(miRNAs).Through differential expression and functional enrichment analyses,followed by qRT-PCR validation,we identified a set of RNA markers that exhibit significant correlations with PMI.Our results revealed distinct degradation patterns among RNA types and demonstrated that integrating multiple RNA markers with stable reference markers enables robust and reliable PMI estimation.Furthermore,by applying principal component analysis(PCA)and partial least squares(PLS)-based models,we developed a quantitative strategy for PMI estimation.These models demonstrated satisfactory predictive performance in independent validation sets.Collectively,our findings refine the current understanding of RNA degradation under postmortem conditions and establish a methodological basis for molecular-based PMI estimation.
Touch DNA,also known as transfer DNA or trace DNA(tDNA),is becoming an integral part of forensic investigations.tDNA is often the only genetic material recovered from a crime scene,as biological material is often missing.The analysis of tDNA is complicated by several major issues that need to be addressed:low quantity,poor quality of the molecule,high risk of contamination,and mixing of DNA profiles.Evidence obtained from tDNA analysis is often considered unreliable,so the forensic protocol should address and overcome the main problems and maximise the usability of the evidence in legal proceedings.This study evaluates the effectiveness of crime scene samples(CSS)and forensic laboratory samples(FLSs)in short tandem repeat(STR)typing using Fisher's exact test.CSS were collected at the crime scene by swabbing sites and objects,while FLSs were obtained by a forensic geneticist under laboratory conditions from material traces seized at the crime scene.The samples were taken from actual cases investigated by the police of the Czech Republic.The results,analysed using the R software,showed that 56.2%of the tDNA samples could provide STR profiling results of the same quality as samples with proven presence of biological material(semen,saliva and blood).The study demonstrated that tDNA sampling is practical and that DNA profiles generated from tDNA samples have the potential to identify persons at the individual identification level.The study highlighted the need for refinement and development of new techniques to determine the amount of biological tDNA material in the traces of the crime scene and also in the examination of the material traces in the forensic laboratory,as this direction is desirable given the number of traces examined compared to the other biological materials mentioned above.
Method of moments(MoM)and identity by descent(IBD)segment methods are two popular algorithms for kinship inference in investigative genetic genealogy(IGG).However,there is no consensus on how or when to use them,and different criteria of IBD lengths or kinship coefficients are applied to consider a true match.In this study,we compared the performance of KING(representing the MoM method)and IBIS(representing the IBD segment method)for kinship inference in homogeneous populations,admixed populations,and sparse SNP panels.Both simulated and real family data were used.In addition,an equivalent threshold-based method for kinship inference was also proposed,based on either the kinship coefficients or the lengths of IBD segments.Results showed that the overall accuracies were 64.97%for homogeneous population and 54.71%for admixed population with KING while they were 72.92%and 70.88%,respectively,with IBIS.IBIS showed low recall and precision rates when the SNP number was below 164k.In contrast,KING performed still robustly with SNP number as low as 10k.Similar results were obtained with real family data.In conclusion,the two methods perform differently and different methods should be used for different scenarios.If the DNA is of high quality or the samples are from admixed populations,the IBD segment method is recommended.If the samples are of low quantity and/or quality,MoM is more appropriate.For more complex scenarios,both methods can be tried.More importantly,there is an urgent need to develop new algorithms to address related issues.
The hide beetle, Dermestes maculatus (DeGeer, 1774), is a forensically significant insect commonly associated with decomposing remains and is also a pest of stored animal products. It typically appears during the later stages of carcass decomposition and can aid in estimating long-term postmortem intervals (PMI). While many studies have focused on its development at constant temperatures, there is limited research on it under uncontrolled conditions. This study investigated the developmental patterns of D_ maculatus, from egg to adult under indoor natural conditions during two distinct seasons: the post-monsoon (mean temperature range: 20.6 degrees C-32.5 degrees C; relative humidity: 43.3%-72.0%) and winter-spring (mean temperature range: 10.0 degrees C-30.6 degrees C; relative humidity: 34.3%-87.5%) periods. The life cycle duration varied significantly, with 39.02 +/- 3.37 days in the post-monsoon period and 126.80 +/- 4.47 days in the winter-spring period. Notably, development was recorded at temperatures below 15 degrees C in fluctuating environments. Morphometric analysis of larval body length and width was performed throughout development. Temperature and humidity were identified as critical factors influencing larval growth and overall development rates, which are essential considerations in forensic casework. A machine learning approach utilizing XGBoost models was employed to predict the age of D_ maculatus based on morphometrics, temperature, and humidity. The models demonstrated high accuracy, with R2 values of 0.99. SHapley Additive exPlanations (SHAP) analysis was performed to interpret the model and explore feature interactions. This research contributes valuable data on D_ maculatus development under varying environmental conditions, enhancing its utility in forensic investigations and potentially improving the accuracy of PMImin estimations in cases where this species is present.
Occupational accidents(OAs)are stressful life events with the potential to trigger temporary or long-lasting psychological symptoms that can affect the capacity to resume work and/or the extent of permanent professional disability(PD).This study aimed to analyse the relationship between psychological symptoms reported at the end of the OA recovery and rehabilitation process and both professional reintegration and PD.A cross-sectional study using a convenience sample(n = 101)was conducted over a 6-month time span at a Portuguese insurance company after the medico-legal examination.The participants underwent a semi-structured interview and completed self-reported psychological measures.Information regarding current professional status(active vs.inactive)and the assignment of a PD rate(with vs.without)was collected.Most of the participants(80.2%)were already professionally active,and 54.5%were assigned a PD.With respect to the psychological measures,the participants reported a moderate or above level of self-perceived in the following:emotional pain(71.3%),difficulties at work and social adjustment(WSA)(61.4%),anxiety(40.6%),and depression(35.6%).Reported symptoms of depression and WSA difficulties were greater in the professionally inactive group and were correlated with professional status.Reported symptoms of WSA difficulties were shown to be good predictors of professional status.The PD-assigned group presented higher WSA difficulty levels and was a good predictor of PD attribution.The findings shed light on the potential impact of reported depression symptoms and WSA difficulties on professional reintegration,stressing the importance of psychological assessment and support(when needed)during recovery and professional rehabilitation processes.
Latent fingerprints are crucial for suspect identification and crime scene reconstruction.While 1,2-indanedione-based fingerprint development techniques demonstrate high sensitivity in reacting with amino acids present in fingerprint residue and good adaptability to porous substrates,their practical value is constrained by environmental instability,operational complexity,and reliance on high-temperature treatments.Drawing inspiration from the enhanced visualisation of fingerprints deposited by skincare product users,this study innovatively introduced propylene glycol and glycerol as cosolvents into the 1,2-indanedione formulation.The hydroxyl groups of these additives form stable hemiketal adducts with 1,2-indanedione's carbonyl moieties,thereby accelerating reaction kinetics with amino acids and amplifying fluorescence intensity.The optimisation results indicate that the new formulation,incorporating 2 mL of propylene glycol as a cosolvent,eliminates thermal treatment and boosts the fingerprint development rate on copy paper from 71%to 93%.Additionally,the optimised 1,2-indanedione working solution reduces methanol content by 75%,achieving dual benefits of reduced toxicity and superior fluorescence emission.Systematic evaluations confirm the method's robustness across diverse substrates and its ability to develop aged fingerprints(up to 8 months under ambient conditions)without thermal assistance.Crucially,comparative analyses of pre-and post-treatment document examination and biological assays confirm that the optimised protocol not only enhances fingerprint visualisation but also preserves forensic integrity for downstream analyses.This breakthrough establishes a practical framework for integrating the optimised 1,2-indanedione formulation into multimodal forensic workflows.
Utilisation of necrophagous larvae in forensic investigations has been gaining popularity. To ensure its admissibility as forensic evidence in the court, the development of validated simultaneous analytical methods specific for this matrix proves forensically relevant. Hence, this present research reported, for the first time, the specifically developed and validated online preconcentration electrokinetic supercharging with capillary zone electrophoresis (EKS-CZE) for analysing cocaine and morphine in necrophagous larvae. The optimum conditions were background electrolyte (30 mmol/L disodium phosphate containing 20% methanol (v/v)), hydrodynamic injection of sodium chloride (40 mmol/L, 5 kPa, 60 s) as the leading electrolyte, electrokinetic injection of the sample (20 s, +10 kV) and the hydrodynamic injection of L-alanine (100 mmol/L, 5 kPa, 10 s) as the terminating electrolyte. The separation was conducted at +25 kV with ultraviolet detection at 200 nm. The linear range for cocaine (58-500 pg/kg) and morphine in larvae (72-500 pg/kg) demonstrated the coefficient of determination (R2) greater than 0.995. For cocaine and morphine, the limits of detection were 19.14 pg/kg and 23.83 pg/kg, and the limits of quantitation were 57.99 pg/kg and 72.20 pg/kg, respectively. The relative standard deviation (RSD) values (intra-and inter-day repeatability) were below 10% for both analytes, with sensitivity enhancement factor values of 680 (cocaine) and 620 (morphine), respectively. This novel, optimised, and validated simultaneous EKS-CZE method may prove to be applicable for the determination of cocaine and morphine with potential applications in forensic entomotoxicological casework.
Personal identification is an important application of forensic DNA identification,but its success rate is often constrained by the size of the available DNA database.Forensic DNA phenotyping(FDP)can reveal the externally visible characteristics(EVCs)of unknown individuals,thereby narrowing the scope of investigations.However,current phenotypic prediction systems mainly focus on pigmentation traits and lack data specific to Chinese populations.Based on previous phenotypic studies,we designed a phenotypic detection system containing 19 SNP loci,which can detect 13 phenotypes by capillary electrophoresis.Sensitivity,degradation,species specificity,and ancestral inference were assessed.A population study was conducted using samples from 110 individuals from Northern China.The total discrimination power(TDP)of this system was 0.999 996 560 449 156,and a complete map from the total input DNA was as low as 250 pg.This system was species-specific,resistant to PCR inhibition,and capable of detecting degraded samples.All alleles were detected from artificially highly degraded DNA after 100 min of boiling water bath treatment.Additionally,the replication study of the Chinese population shows that the inference model built based on the SNP genotyping result in the composite detection system has high prediction accuracy in a variety of phenotypes,such as Asian flushing,body odour and facial features.The AUC values of the Asian flushing and body odour model were 0.87 and 0.98,respectively,and the related SNPs can explain 43%and 51%of their phenotypic variations,respectively.However,the AUC values of the prediction models for other phenotypes in the Chinese population were<0.8.The combined detection system of 19 SNPs and 13 phenotypes can be used for forensic characteristic phenotype inference.To an extent,it can be used to detect degraded samples,identify individuals,and infer ethnicity.
This study aimed to improve age prediction in a Danish cohort of 150 individuals by in-depth analyses of DNA methylation sequencing data.In previous work,11 well-known age-associated CpGs located on 10 PCR amplicons associated with 10 distinct genes were selected,and a support vector machine model with a polynomial function(SVMp)was developed for age estimation in blood.The 10 amplicons were PCR-amplified after bisulphite conversion and the methylation levels were assessed by massively parallel sequencing.The 10 amplicons contained a total of 73 CpG sites,of which 63 CpG sites were shown to be medium to highly associated with age in this work(Pearson correlation coefficient,|r| > 0.3).More than 70 000 SVMp models with various combinations of the 63 CpGs were tested to identify the model with the lowest mean absolute error(MAE)and root mean square error(RMSE)in training and test datasets from the Danish cohort.A final model with 34 CpGs(SVMp-34CpG)was selected.The SVMp-34CpG model showed considerable improvement over many other forensic prediction models and achieved mean absolute errors of 1.64 years and 1.76 years for the training and test datasets,respectively.The SVMp-34CpG model indicated robust generalization and minimal prediction bias across the 18-50 years age range(MAE:1.47 years),although slightly higher errors were observed for individuals aged 50-70 years(MAE:2.62 years).This was most likely due to epigenetic drift,together with the small number of individuals analysed in this age group.Compared to the previous 11-CpG model,the SVMp-34CpG model showed superior accuracy in the Danish cohort by predicting the age of 91%of the individuals within 4 years of their actual age,versus 68%for the previous model.
This rapid communication article highlights a groundbreaking 24-month technical residency programme in forensic sciences designed for recent graduates from diverse fields. This pioneering initiative, supported and funded by the Secretariat of Public Security (Secretaria de Estado da Seguran & ccedil;a P & uacute;blica, SESP) of the state of Paran & aacute; in southern Brazil, aimed to bridge the gap between academic education and training and practical forensic expertise. Agroup of 46 candidates was selected to integrate into the Scientific Police, working under the direct supervision of experienced forensic expert officers while concurrently participating in a specialized programme at the State University of Maring & aacute; (Universidade Estadual de Maring & aacute;, UEM). Throughout the residency, participants were immersed in real-world forensic investigations, applying advanced methodologies and contributing to the efficiency and accuracy of forensic examinations. By the programme's conclusion, 33 residents had successfully graduated, earning official certifications that enhanced their qualifications for careers in forensic science. Beyond individual professional development, this residency programme significantly strengthened forensic capabilities in Paran & aacute;, setting a precedent for structured, high-level forensic education and training in Brazil. Its impact extends to the broader criminal justice system by fostering a new generation of well-trained forensic professionals, ultimately improving the quality and reliability of forensic investigations nationwide. For future editions, we recommend refining the participant selection process to prioritize candidates with strong scientific knowledge. To minimize attrition from the programme, we recommend increasing stipends and benefits for those who complete the residency.
A methodology to estimate shooting distance based on the analysis of inorganic components of gunshot residues (GSRs) was developed using inductively coupled plasma-mass spectrometry (ICP-MS). Test shots using a Type 79 micro rifle (250 mm barrel length and 7.62 & times; 25 mm cartridges) were made at distances between 10 and 90 cm. A series of mathematical models relating shooting distance to the content of elements Sn, Sb, Ba, and Pb in the GSRs was developed. These models were developed using data from a series of shots performed against a 45 & times; 45 cm white 100% polyester cloth. The target was sampled at five radial distances (in increasing 10 mm steps) and four perpendicular directions. A logarithmic correlation was observed between the shooting distance and the average content of elements Sn, Sb, Ba, and Pb at radial distances of 1.5 cm and 5.5 cm from the entrance hole, for shooting distances up to 90 cm.
