Wikipedia
Polilight
The Polilight is a portable, high-intensity, filtered light source used by forensic scientists and others to detect fingerprints, bodily fluids and other evidence from crime scenes and other places.
Similar products to the Polilight include the Foster + Freeman Crime-lite, Ultralite ALS and the Optimax Multilite, all of which use light-emitting diodes to produce high-intensity light of varying wavelengths.