When Tools Get Blamed Instead of Technique: The Training Gap in Forensic Lighting
In today’s age, speed matters, and when it comes to forensic investigations, CSM’s, CSI’s and examiners are under pressure to get results, process the scene and get the hell out, after all, time is money. There’s new equipment in the forensic equipment market claiming to do the work in half the time, press a button and hey presto the image is captured and you move on. This kit has its place, and can work well in the lab environment, but out at a crime scene, it can be a different matter. Quite often at a crime scene, it’s pain taking slow work looking for fingermarks and other trace evidence. Looking at a range of surfaces, colours and contaminates.
You need an arsenal of lighting tools to be able to search properly. So lights beyond the ubiquitous torch are required – the ball light, round LED lights, ring light, panel light are just a few of the lights that can help the examination of a crime scene. The problem comes with the use of these specialist lighting techniques. After all it’s only a light source in a different shape?
In forensic work, even the best tools can be unfairly judged if they are used incorrectly. Across the field, there’s a growing murmur of frustration about certain light sources—particularly lasers and ball or LED lights—being described as “ineffective” for crime scene or fingermark examination. The issue isn’t that the equipment falls short; it’s that many practitioners haven’t had the structured training needed to unlock what these technologies truly offer.
Lighting is central to forensic imaging. The way light behaves—its wavelength, angle, intensity and polarisation—governs how evidence becomes visible or invisible to the eye or camera. But equipment like high-intensity lasers or multi-wavelength LED systems demands both technical understanding and practical control. Used correctly, they can reveal fingermarks, biological traces and trace evidence with unmatched clarity. Used incorrectly, they can appear little better than a strong torch.
The illusion of ineffectiveness
Feedback from untrained or minimally trained users often follows a similar pattern: lasers are “too bright,” “don’t show anything useful,” or “take too long to set up.” Compact ball or LED lights are sometimes dismissed as “gimmicks” or “no better than household lamps.” These comments share a common thread: frustration rather than fault.
For instance, a forensic laser tuned to a specific wavelength can make certain dyes or latent residues fluoresce vividly—if the operator understands which barrier filter to use, what distance to hold, and how to reduce ambient reflections. Without that understanding, a scene examiner may simply see glare or uneven illumination, assume the device isn’t capable, and return to a less discriminating light source. The conclusion becomes “the laser doesn’t work” when the real issue is a knowledge gap.
Similarly, portable ball or LED lights rely on correct positioning, wavelength selection, and surface control. Their power lies in flexibility—easy movement around an exhibit to detect subtle ridge detail, textiles patterns, or contamination marks. However, if used without considering angles of incidence or the correct spectral range, their advantages are lost. The lights might then appear weak compared to traditional UV lamps or flash photography, leading to misjudged reputations.
Where training closes the gap
Well-designed training transforms how practitioners perceive and use these tools. A properly trained examiner learns:
- How wavelength relates to evidence type and fluorescence response.
- How to select and combine filters.
- How camera settings (ISO, white balance, exposure time) interact with light output.
- How to interpret what is seen through barrier goggles versus camera detection.
- How to adjust angles and distance to avoid specular reflection.
- Other times you want the specular and semi specular reflections, the skill is knowing how to use them effectively.
Through hands-on demonstration and side‑by‑side comparison, practitioners quickly see that these devices are not inconsistent or unreliable—they are precise instruments that reward understanding. Once a practitioner learns to tune and control light properly, what seemed “ineffective” often becomes indispensable.
Consequences of poor technique
When lighting is misapplied, the consequences extend beyond wasted effort. Misuse can lead to missed evidence, inadequate photographic documentation, and false conclusions about what a technology can or cannot reveal. Forensic science relies on reproducibility and proper documentation; when an examiner lacks the foundation to achieve consistent results, evidence quality and credibility can suffer.
Moreover, technology suppliers and laboratories face reputational risks. A powerful but misunderstood device quickly acquires an undeserved label of poor value. Procurement budgets then become skewed toward less effective but more familiar tools, creating a cycle where innovation stalls simply because training was overlooked.
Training as investment, not expense
The real solution lies in embedding training into procurement, induction, and refresher programmes. Equipment should not arrive without structured demonstration, applied exercises, and documented proficiency checks. Licensing a new laser or light source without ensuring operator competence almost guarantees disappointment.
Manufacturers, educators, and forensic managers share responsibility here. Tool suppliers must explain not only how their devices function, but also how scene lighting interacts with surface materials. Training providers must bridge the classroom and the exhibit room—turning light theory into observable results. And individual practitioners must recognise that the “secret” to effective illumination is rarely more equipment—it is understanding.
Reframing the discussion
When feedback arises claiming that lasers or LED units “don’t work,” it’s worth reframing that criticism into a constructive opportunity. What training has the practitioner received? Do they understand the operational parameters of the device? Could the problem stem from environmental conditions, surfaces, or filter mismatch?
By shifting the conversation from tool-blaming to technique-building, the forensic community can safeguard both effectiveness and confidence in emerging technologies. Every time an investigator learns to use a light source properly, the discipline advances another step toward consistent, evidence‑driven excellence.
Does your lab or CSI team confidently use the following light sources?
- UVA Light (365nm): To induce fluorescence.
- White Light: Both diffuse and collimated* to detect visible marks and specular reflections.
- Blue Laser (445nm) and Green Laser (520nm): For fluorescence and absorption enhancements (e.g., blood on fluorescent surfaces)
If not, contact FTP now to arrange a discussion on how we can help your team with the knowledge gap.
*Collimated light refers to a beam of light where all the rays travel parallel to each other, meaning they spread minimally as they propagate; essentially, it’s light that appears to be coming from an infinitely distant point source, with all rays maintaining the same direction.
Example of collimated light:
- Laser beam: A well-designed laser beam is considered highly collimated as its light rays are nearly perfectly parallel.
- Sunlight from a distant star: stars are very far away, the light reaching Earth can be considered almost perfectly collimated.
