Enhancing trace DNA recovery from disposable face masks: insights from the COVID-19 era and beyond

Trace DNA plays a pivotal role in forensic investigations, serving as a critical tool for linking suspects to criminal activities. During the COVID-19 pandemic, disposable face masks emerged as key items of forensic interest, particularly in cases where suspects used them to conceal their identities. This study evaluates the efficiency of two trace DNA collection methodologies-cotton swabbing and tapelifting-for recovering DNA from face masks. Samples were collected from 50 masks worn by suspects in robbery cases, utilizing the Copan cotton swab (150 C) and the SceneSafe Fast™ minitape (K545). Statistical analysis revealed that minitapes (MT) significantly outperformed cotton swabs (CS), yielding higher DNA concentrations (mean MT: 0.41 ng/µL, CS: 0.17 ng/µL; p < 0.05) and recovering more complete DNA profiles, including full single (FS) and full mixed (FM) profiles (p < 0.05). These findings highlight the superior efficiency of MT, particularly for recovering trace DNA from small or fabric-like surfaces. The study underscores the importance of selecting optimal collection methods in forensic investigations, especially for modern evidence types such as face masks. Recommendations include the routine adoption of minitapes in casework involving face masks and further research into their efficacy on other mask types and under varied environmental conditions. This research offers valuable insights to refine trace DNA recovery strategies, enhancing the reliability of forensic evidence.