Reflected near-infrared photography: Digging deeper into post-mortem examination.

Area of Science:

• Forensic Science
• Medical Imaging
• Photography

Background:

• Post-mortem examinations require accurate visualization and documentation of forensic evidence.
• Standard photography may struggle to capture subtle or obscured evidence.
• Near Infra-Red (NIR) photography presents a potential advancement in forensic imaging.

Purpose of the Study:

• To evaluate the effectiveness of Near Infra-Red (NIR) photography for visualizing forensic evidence during post-mortem examinations.
• To compare NIR photography with Human Visible Spectrum (HVS) photography in a forensic context.

Main Methods:

• Utilized a modified Nikon D5300 DSLR with a 760nm-860nm infrared filter for NIR photography.
• Employed a Nikon D5600 DSLR for HVS photography.
• Examined twenty-six deceased individuals, documenting findings using both photographic techniques.

Main Results:

• NIR photography demonstrated superior visualization of trace evidence, such as blood spots and soil particles on dark clothing.
• External and internal post-mortem findings, including contusions and internal injuries in accident victims, were better visualized with NIR.
• NIR photography proved effective for documenting evidence in cases of road traffic accidents, gunshots, and drowning.

Conclusions:

• NIR photography is the optimal technique for visualizing and photo-documenting forensically relevant post-mortem findings.
• While HVS photography provides substantial documentation, NIR photography offers enhanced visualization of trace evidence and contusions.
• The combination of NIR photography with natural light sources (sunlight, room light) at 760nm-860nm yields the best results for forensic evidence detection.