Gaseous Phase Detection of Latent Fingerprint Using Polycyanoacrylate Depolymerization and Volatile Fluorescent Dye

Abstract

A variety of evidence samples have been brought into the Identiˆcation section of the police for detection of latentˆngerprints. Fumes of cyanoacrylate ester are generally used to detect latentˆngerprints on ‰at surfaces, such as cutlery, in a case of murder. Whiteˆngerprint ridgesˆxed by the fumes are generally stained with dye powder or dye solution.We developed new reagents which can detect latentˆngerprints the same method as using both the fumes of cyanoacrylate ester and ‰uorescent staining. First, polycyanoacrylate ester powder was produced from its monomer and water as an initiator. Then, 5 percent of p-dimethylaminocinnamaldehyde (DMAC) or pdimethylaminobenzaldehyde (DMAB), each of which has volatility and ‰uores-cence that could be excited by ultraviolet light or blue light respectively, was added to the polycyanoacrylate ester powder. The developed reagent depolymerized and yielded monomer at a lower temperature than polycyanoacrylate powder that polymerized in methanol containing 1 water. The mixed DMAC or DMAB can simultaneously stain and give ‰uorescence to the whiteˆngerprint ridge. Added to that, exposing samples to acetic acid vapor for a short time has increased the ‰uorescence intensity and shifted excitation wavelength to a longer one such as ultraviolet to blue

Application of mist to fingermark detection: Misting with high‐boiling‐point liquid containing p‐dimethylaminocinnamaldehyde and cyanoacrylate

“…Each fingermark was divided into four pieces and processed using four different methods: DMAC fuming (a), DMAC/OA/CN misting (b), DMAC/MD/CN misting (c), and DMAC + PCN fuming (d). The composition of the reagent used in (d) and the heating temperature (230°C) are the same as those reported by Shimoda et al [13]. The amounts of reagents used in (a), (b), (c), and (d) were 1.5, 50, 50, and 30 mg, respectively.…”

“…Our second proposition is a misting method using high-boilingpoint liquid containing DMAC and cyanoacrylate for one-step detection of latent fingermarks. Among the one-step fluorescent detection methods developed for latent fingermark detection in recent years, Polycyano UV (Foster and Freeman) [13][14][15], and Lumicyano (Crime Scene Technology) [16][17][18] are already widely used in the field of forensic investigation. The reagent used in Polycyano UV is a combination of DMAB and cyanoacrylate polymer (PCN).…”

“…The reagent used in Polycyano UV is a combination of DMAB and cyanoacrylate polymer (PCN). On the other hand, a reagent combining DMAC and cyanoacrylate polymer has also been reported in the same report [13], but it has not yet been widely used.…”

“…The reagent used in Polycyano UV is a combination of DMAB and cyanoacrylate polymer (PCN). On the other hand, a reagent combining DMAC and cyanoacrylate polymer has also been reported in the same report [13], but it has not yet been widely used. One reason for this is that the volatility of DMAC is lower than that of DMAB, making it less likely to use as a fuming reagent.…”