The forensic science landscape has been significantly transformed by the advent of DNA methylation analysis, offering unparalleled precision in body fluid identification, age estimation, and distinguishing between monozygotic twins. This review delves into the historical evolution, methodological advancements, and the pivotal role of DNA methylation in forensic applications, underscoring its potential in addressing complex forensic challenges. Results: The study detected significant differences in the expression of LINE-1 and FGF7 in blood, and MT2A and FGF7 in saliva, between Egyptian and Yemeni populations, P-value< 0.05. Profound differences were observed in the expression of MT2A, LINE-1, and FGF7 in both blood and saliva samples between males and females, P-value< 0.05. The markers examined in this study demonstrated good sensitivity and specificity for identifying the origin of blood and saliva samples based on nationality and gender, underscoring their potential forensic and biomedical applications. Conclusion: this study offers appreciated visions into the influence of population-specific and gender-based factors on DNA methylation profiles, contributing to the growing body of evidence supporting the use of these molecular markers in forensic investigations and personalized medicine. The findings emphasize the importance of considering these variables in the interpretation and application of DNA methylation data for effective and tailored diagnostic and therapeutic strategies.