Using UV Light for Finding Human Remains: Forensic Research and Field Guide
How ultraviolet, violet, and other wavelengths of light can help searchers locate surface-scattered skeletal remains.
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Searching for Skeletal Remains with Alternate Light Sources
Searching for Skeletal Remains with Alternate Light Sources
Using alternate wavelengths of light to find what may otherwise be difficult to see
Using alternate wavelengths of light to find what may otherwise be difficult to see
Skeletal remains can be surprisingly difficult to detect in the outdoor environment. Bone can blend into leaves, vegetation, soil and other natural materials—even when it is lying directly on the surface. It is not uncommon for materials to return to baseline over a period of time. Returning to baseline is defined as taking on characteristics of an object's surrounding environment, essentially becoming more camouflaged with time.
Alternate Light Sources (ALS) provide searchers with another way to look.
Certain wavelengths of light can cause bone to fluoresce, producing a visible contrast between skeletal material and its surroundings. This can make some exposed or partially exposed bones substantially easier to recognize, particularly under nighttime conditions.
Research and field experience by the Search and Rescue Tracking Institute (SARTI), Virginia Commonwealth University and other collaborators have demonstrated the potential of ALS as a tool for searching for surface-scattered skeletal remains.
Keep scrolling to explore the science, research and field methods behind ALS-assisted skeletal-remains searches.
Why Does Bone Glow?
Why Does Bone Glow?
Certain components of collagen in bone can interact with particular wavelengths of light and produce fluorescence.
In simple terms, light energy is absorbed by the material, temporarily changes its energy state, and is then released as light at a different wavelength.
The process can be described in five steps:
Absorption → Excitation → Relaxation → Emission → Detection
Understanding fluorescence helps explain why skeletal remains can become much more visually apparent under certain alternate light sources.
What does fluorescing bone look like?
What does fluorescing bone look like?
White light at night
White light at night
Photo showing a human femur obscured by green vegetation at night
UV Light
UV Light
Photo showing the same photo as on the left, but using a UV light source
Ultraviolet ALS is Effective for Detecting Bone Fragments
Bone Fragments in Daylight
Bone Fragments in Daylight
Photo showing bone fragments mixed with dirt, stone, shell fragments, grass, pine needles, pine cones, etc.
Bone Fragments with UV ALS
Bone Fragments with UV ALS
Photo showing bone fragments mixed with dirt, stone, shell fragments, grass, pine needles, pine cones, etc.
Even Teeth Fluoresce
Even Teeth Fluoresce
Teeth can also produce a fluorescent response under ALS.
One interesting observation from our testing is that the roots of teeth fluoresce more strongly than the enamel.
A Fluorescent Bone Is Not Necessarily Human
A Fluorescent Bone Is Not Necessarily Human
ALS can make bone easier to see—but fluorescence does not tell you what species the bone came from.
Human bones fluoresce.
Deer bones fluoresce.
Bear bones fluoresce.
Other animal bones can fluoresce as well.
That means ALS is a search and detection tool, not an identification method.
Once a bone is located, comparative osteology remains essential for determining whether it is human or non-human.
Day/Night Demonstration of 110-foot visibility using 385-395 nm UV ALS
Day/Night Demonstration of 110-foot visibility using 385-395 nm UV ALS
Camera: Nikon D3200 DSLR
Shutter speed: 25 seconds
Aperture: f/11
ISO: 400
Focal length: 35 mm
Flash: Minolta Maxxum 4000 FA used off camera (2 full-power flashes)
ALS: uvBeast V3 385-395 nm UV held 6-feet above ground "painting" the objects
Test object: human ribs placed at 10-foot increments from the camera from 10- to 110-feet
Using ALS in the Field
Using ALS in the Field
Finding skeletal remains with an alternate light source requires more than simply turning on a UV flashlight and walking through the woods.
Successful ALS searching involves planning, appropriate search spacing, darkness, equipment preparation, calibration, navigation and careful documentation.
Our field procedures have developed through experimentation and operational searches conducted by SARTI.
What Does the Research Show?
What Does the Research Show?
Explore a growing collection of research on alternate light sources, bone fluorescence, and the detection of skeletal remains. This resource brings together research conducted by SARTI members and collaborators alongside published work from researchers and forensic scientists around the world.
From controlled experiments and field studies to case reports and investigations into bone fluorescence, these publications provide a broader look at the science behind using alternate light sources to search for skeletal remains.
Original Ultraviolet Light posting: September 17, 2023 Updated: September 29, 2026
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