Easy to Use
Collecting forensic evidence with the cold light kit is just as easy as it is effective. Fingerprints on crumpled aluminum foil, for example, are first of all sprayed with cyanoacrylate and then treated with a fluorescent solution of methanol and safranine. The solution makes it possible to visualize even low-contrast prints under cold light, provided the light passes through an appropriate fluorescence excitation filter first. Some of the excitation is converted by the solution-treated print into fluorescent light. During analysis of the fingerprints the barrier filters are used. These absorb any undesirable excitation light or ambient light and only allow the fluorescent light being emitted by the fingerprint to pass into the detector. The result of the procedure is that fingerprints appear clearly and can be photographed easily.
The advantages of the cold light kit have convinced forensic specialists in many countries. For example, the German Federal Criminal Police Office in Wiesbaden uses the KL 2500 LCD forensic kit. “We use the unit in our laboratories not only when searching for fingerprints but also when collecting evidence such as hair, fibers, and blood. Often such microscopic items can only be visualized under cold light,” explains a BKA spokesman. The Romanian police has equipped 50 crime scene vehicles with cold light sources and the Forensic Science Services Metropolitan Laboratory in London has requested a kit for test purposes. As far as Walter Körner from the SCHOTT Fiber Optics Division is concerned, this is clear recognition of the product: “After all, that institution works for Scotland Yard, the very first police department to use fingerprints in tracking down criminals”.