Longwave Reflected UV for the Enhancement of Cyanoacrylate Fumed Fingerprints
Research conducted by Foster+Freeman, has added further weight to the argument that Longwave Reflected-UV (LWUVR) imaging should be considered the first choice examination technique when searching for fingerprints on superglue-fumed evidence.
In a paper accepted for publication by Forensic Science International, tests on a variety of evidence types emphatically demonstrate the benefits of LWUVR imaging for the visualization of cyanoacrylate fumed (CAF) prints when compared with conventional techniques.
(A) white light illumination, (B) LWUVR, and (C) BY40 fluorescence examination
First, a longwave UV light source is directed onto the evidence. As the UV light hits the evidence, it is then reflected and absorbed in differing quantities by the cyanoacrylate fingerprint and the surface to which it has adhered. This difference creates a contrast between print and surface that is invisible to the naked eye but clearly visible when observed using a UV-ready digital camera.
In the tests, the LWUVR technique continually outperformed existing techniques and was demonstrated to be extremely simple, versatile and effective method of significantly enhancing fingerprint ridge detail.
Unlike the traditional method of using a fluorescent dye to create contrast between fingerprint and background; a process that can be messy, time-consuming, potentially damaging to evidence, and costly in terms of manpower and chemical usage, LWUVR imaging can be used immediately after fuming to reveal fingerprints of incredible quality with no further chemical treatment required.
Simple and non-destructive, the LWUVR imaging technique requires the examiner to search for and examine evidence within the UV spectrum.