Persistence of spermatozoa on decomposing human skin: a scanning electron microscopy study

Area of Science:

• Forensic Science
• Microscopy
• Thanatology

Background:

• Spermatozoa detection is crucial in legal investigations, yet research often overlooks external semen deposition on skin.
• Advanced techniques like scanning electron microscopy (SEM) require further investigation for forensic applications.

Purpose of the Study:

• To evaluate the efficacy of SEM in detecting spermatozoa on decomposed skin samples.
• To determine the persistence of spermatozoa on skin over time in post-mortem cases.

Main Methods:

• Skin samples with applied semen were analyzed using light microscopy and SEM over 91 days.
• Control samples (no semen) and positive samples were examined.
• Light microscopy was used for initial detection, while SEM was employed for prolonged analysis.

Main Results:

• Light microscopy failed to detect spermatozoa after 12 days.
• SEM successfully identified spermatozoa on decomposed skin samples for up to 84 days.
• This indicates the prolonged viability of sperm structures in decomposing tissues.

Conclusions:

• SEM is a valuable tool for detecting spermatozoa on decomposed skin in forensic investigations.
• The study highlights the persistence of sperm structures, extending their detection window significantly.
• SEM offers enhanced capabilities for semen detection in challenging forensic scenarios.