Sriwijaya Journal of Forensic and Medicolegal

Reading the Epigenetic Clock: A Comparative Analysis of DNA Methylation Markers for Age Estimation in Semen, Saliva, and Touch DNA

Febria Suryani — 2025-07-24

Introduction: The capacity to predict an individual's age from biological evidence constitutes a significant advancement in forensic intelligence. DNA methylation, a stable epigenetic mark, provides a molecular basis for "epigenetic clocks." However, the operational reliability of these clocks necessitates rigorous validation across diverse biological samples and populations, particularly for challenging, low-template touch DNA evidence.

Methods: Following approval from the Ethical Committee of CMHC Indonesia (No. 128/EC/CMHC/2023), we recruited 150 healthy Indonesian male volunteers aged 18-65. Semen, saliva, and high-yield standardized touch DNA samples were collected. DNA was extracted, quantified fluorometrically, and subjected to bisulfite conversion with efficiency controls. The methylation levels of a curated five-CpG panel (ELOVL2, FHL2, TRIM59, KCNQ1DN, C1orf132) were quantified using a rigorously controlled pyrosequencing workflow. Body-fluid-specific age prediction models were developed using multiple linear regression, validated with 10-fold cross-validation, and assessed for statistical assumptions including multicollinearity.

Results: The models for semen and saliva demonstrated high predictive accuracy, yielding Mean Absolute Deviation (MAD) values of 3.19 years (R²=0.94) and 3.55 years (R²=0.92), respectively. The model developed from high-yield touch DNA was less precise but still highly informative, with a MAD of 5.49 years (R²=0.85). All models satisfied the assumptions of linear regression, with Variance Inflation Factors below 2.5 indicating low multicollinearity. The 95% prediction intervals were narrowest for semen, reflecting its superior precision.

Conclusion: This study validates a robust, targeted epigenetic panel for age prediction in a Southeast Asian population. We present highly accurate, tissue-specific models for semen and saliva, suitable for immediate consideration in forensic casework. The touch DNA model, while requiring cautious interpretation, provides a valuable framework for generating investigative leads from trace evidence. Our findings underscore the critical importance of tissue-specific modeling and provide a detailed methodological and statistical blueprint for the responsible implementation of forensic age estimation.

The Impact of Postmortem Interval on the Reliability of Forensic Autopsy Evidence in Murder Cases: A Comprehensive Analysis in Nairobi, Kenya

Stephen Kase — 2023-05-02

Introduction: Postmortem interval (PMI) significantly impacts the accuracy and interpretation of forensic autopsy evidence, especially in murder cases. In Nairobi, Kenya, where resources and infrastructure may be limited, understanding the relationship between PMI and evidence reliability is crucial for effective investigations and prosecutions.

Methods: A retrospective analysis was conducted on 150 murder cases in Nairobi between 2018 and 2023. Cases were stratified based on PMI (early PMI <24 hours, intermediate PMI 24-72 hours, late PMI >72 hours). Autopsy reports were reviewed to assess the reliability of evidence related to the cause of death, manner of death, and identification. Statistical analyses were performed to examine the correlation between PMI and evidence reliability.

Results: As PMI increased, the reliability of certain forensic evidence decreased significantly. Early PMI cases showed the highest reliability for determining the cause of death, manner of death, and identification. In contrast, late PMI cases often presented challenges in interpreting evidence due to decomposition, scavenging, and environmental factors. This led to uncertainties in determining the cause and manner of death, particularly in cases involving blunt force trauma or asphyxia.

Conclusion: This study highlights the critical impact of PMI on the reliability of forensic autopsy evidence in murder cases in Nairobi. Early PMI examinations are essential for obtaining accurate and reliable evidence, especially in resource-limited settings. Standardized protocols, improved infrastructure, and ongoing training for forensic pathologists are crucial to mitigate the challenges associated with PMI and ensure justice in murder investigations.

Barotrauma in Technical Diving: An Exploration of Risk Factors and Preventive Measures in Raja Ampat, Southwest Papua, Indonesia

Lusiana Saallo — 2023-05-02

Introduction: Technical diving, while offering an unparalleled exploration of underwater environments like Raja Ampat's biodiverse reefs, presents inherent risks, with barotrauma being a major concern. This study aims to analyze barotrauma incidents among technical divers in Raja Ampat, identify risk factors, and propose preventive measures.

Methods: A retrospective analysis of barotrauma cases (2018-2023) was conducted in collaboration with local dive centers and medical facilities. Data collected included: demographics, dive profiles, equipment, pre-existing conditions, symptoms, and treatment. Statistical analysis was performed to identify significant associations.

Results: A total of 42 barotrauma cases were identified (ear: 69%, sinus: 21%, lung: 10%). Significant risk factors included: rapid ascents (p<0.01), inadequate equalization techniques (p<0.05), and pre-existing conditions like allergies or upper respiratory tract infections (p<0.05). Most cases were mild to moderate and managed with conservative treatment.

Conclusion: Barotrauma remains a significant risk in technical diving in Raja Ampat. Strict adherence to safe diving practices, comprehensive pre-dive medical evaluations, and targeted diver education programs are crucial to mitigate these risks.

The Impact of Delays in Reporting on the Recovery and Interpretation of Sperm Evidence in Sexual Assault Cases in Bangkok, Thailand

Chris Siriraj — 2023-05-02

Introduction: The timely reporting of sexual assault cases is critical for the preservation and effective analysis of forensic evidence, especially sperm evidence. In Bangkok, Thailand, delays in reporting are common due to various socio-cultural factors. This study aimed to investigate the impact of such delays on the recovery and interpretation of sperm evidence in sexual assault cases.

Methods: A retrospective analysis was conducted on 150 sexual assault cases reported in Bangkok between 2018 and 2023. Cases were categorized based on reporting delay: less than 24 hours, 24-72 hours, and more than 72 hours. The recovery rates of sperm from various anatomical sites and the quality of DNA profiles obtained were compared across the groups. Additionally, a survey was conducted among forensic practitioners in Bangkok to assess their perceptions of the challenges associated with delayed reporting.

Results: The study found a significant decline in sperm recovery rates with increasing reporting delays. In cases reported within 24 hours, sperm recovery rates were highest, particularly from vaginal swabs. The quality of DNA profiles obtained also showed a similar trend, with delays leading to increased degradation and difficulties in interpretation. The survey revealed that forensic practitioners perceive delayed reporting as a major challenge, impacting their ability to provide conclusive evidence in sexual assault cases.

Conclusion: Delays in reporting sexual assault cases in Bangkok significantly impact the recovery and interpretation of sperm evidence. Efforts to encourage prompt reporting, coupled with improved forensic techniques for analyzing degraded samples, are crucial for enhancing the investigation and prosecution of sexual assault cases in the region.

Breaking the Cycle: A Medicolegal Analysis of the Effectiveness of Interventions in Preventing Domestic Violence Recidivism in Dhaka, Bangladesh

Mohammed Ayash — 2023-05-02

Introduction: Domestic violence remains a pervasive issue globally, and Dhaka, Bangladesh, is no exception. This study aimed to examine the effectiveness of various interventions in preventing recidivism among domestic violence perpetrators in Dhaka.

Methods: A retrospective cohort study was conducted involving 300 individuals convicted of domestic violence between 2018 and 2023 in Dhaka. Data were collected from court records, police reports, and intervention program records. Recidivism was defined as a subsequent conviction for domestic violence within three years of the initial conviction. The impact of interventions, such as batterer intervention programs, counseling, and legal sanctions, on recidivism rates was analyzed using Cox proportional hazards regression models.

Results: The overall recidivism rate was 32%. Participation in batterer intervention programs was associated with a significant reduction in recidivism (Hazard Ratio [HR] 0.52, 95% Confidence Interval [CI] 0.35-0.77). Counseling also demonstrated a modest protective effect (HR 0.71, 95% CI 0.53-0.95). Legal sanctions, such as restraining orders and probation, were not independently associated with reduced recidivism.

Conclusion: Batterer intervention programs and counseling show promise in reducing domestic violence recidivism in Dhaka. A multi-pronged approach incorporating these interventions, along with enhanced legal and social support systems, is crucial for effectively breaking the cycle of domestic violence.