This article evaluates the criteria for diatom testing in forensic investigations, focusing on drowning cases. Diatoms, unicellular algae found in aquatic environments, are critical to the determination of drowning because water containing diatoms is inhaled during submersion. The primary objectives include defining the exact amount and type of tissue to be analyzed, expressed in terms of diatom concentration relative to tissue weight, and detailing the conditions under which water samples are collected to study the diatom flora at the site. In addition, the importance of accurately identifying diatom taxa and comparing them by unit weight is emphasized. To improve the reliability of diatom testing, the study discusses advanced methods such as microwave digestion, vacuum filtration, and automated scanning electron microscopy (MD-VF-Auto SEM), which offer higher sensitivity and specificity. The integration of DNA sequencing and deep learning techniques is explored, offering promising improvements in diatom detection and classification. These advances aim to reduce false positives and improve the accuracy of determining drowning as the cause of death. The article highlights the need for standardized protocols for diatom testing to ensure consistency and reliability. By incorporating new technologies and refining existing methods, the forensic application of diatom testing can be significantly improved, allowing for more accurate and reliable conclusions in drowning investigations.