Forensic science has advanced significantly with the integration of molecular life sciences into criminal investigations. One of the most innovative approaches is microbial fingerprinting, which relies on analyzing unique microbial communities associated with humans and environments to establish forensic links between suspects and crime scenes. ⸻ Concept of Microbial Fingerprinting Microbial fingerprinting refers to the unique pattern of microorganisms, particularly bacteria, that inhabit human skin, oral cavity, respiratory tract, and surrounding environments. These microbial communities vary among individuals due to genetics, lifestyle, and environmental exposure, creating a distinctive biological signature for each person. ⸻ Sources of Microbial Evidence at Crime Scenes Microbial fingerprints can be collected from: • Frequently touched surfaces such as weapons, door handles, and mobile phones. • Clothing and fabrics. • Soil, dust, and indoor air. • Invisible skin or sweat residues. This makes microbial evidence especially valuable when human DNA or fingerprints are absent. ⸻ Laboratory Techniques for Microbial Analysis The analysis of microbial fingerprints involves advanced molecular biology techniques, including: • 16S rRNA gene sequencing for bacterial identification. • Next-Generation Sequencing (NGS) technologies. • Bioinformatics tools for microbial profile comparison. Samples from crime scenes are compared with those from suspects to assess similarity and possible contact. ⸻ Role in Linking Suspects to Crime Scenes Microbial fingerprinting can: • Associate individuals with specific locations even after cleaning. • Estimate whether a suspect was present at a particular place. • Support or exclude traditional forensic evidence such as DNA or fingerprints. Studies have shown that microbes transferred from human skin can persist on surfaces for extended periods. ⸻ Challenges and Limitations Despite its potential, microbial fingerprinting faces challenges such as: • Environmental influences on microbial populations. • Limited comprehensive microbial databases. • Lack of universal legal acceptance in forensic courts. ⸻ Conclusion Microbial fingerprinting represents a promising frontier in forensic science. It offers a powerful supplementary tool for linking suspects to crime scenes, particularly in cases where conventional evidence is lacking. Continued research and technological advancements are expected to enhance its reliability and forensic applicability in the future. Al-Mustaqbal University – the first university in Iraq.
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