Latent Fingerprint Development with Genipin and Lawsone

• Main Authors: Huang, Ya-Ju, 黃雅如
• Other Authors: Yang, Chao-Kai
• Format: Others
• Language: zh-TW
• Published: 1040
• Online Access: http://ndltd.ncl.edu.tw/handle/66397528371417656365

碩士 === 中央警察大學 === 鑑識科學研究所 === 103 === Fingerprint is currently one of the most crucial evidence for personal identification in criminal cases and therefore, up to present, dozens of fingerprint developed methods and techniques for developing latent fingerprints have been published. In the practical field, ninhydrin reagent has always been the most common used method and technique for developing latent fingerprints on porous surfaces. The sense of environmental friendly and health consciousness gradually rise in recent years, researching for solvent-free latent fingerprint technique and natural reagents is needed consequently. Firstly, the two published natural-extracted latent print reagents were examined and accessed on their ability to react with most dominated amino acids in fingerprint, serine. In the experiment, genipin was found to have better sensitivity than lawsone. Genipin can also produce better results on the samples which were deposited for several different days than Lawsone. However, the product of both genipin and lawsone reacting with serine could last at least 1 month without degradation. Therefore, genipin was suggested to be a better nature-extracted latent print reagent. Secondly, for the purpose of developing latent fingerprints with a more environmentally friendly way, the idea of using low vacuum sublimation and nature extracted reagents to enhance the latent fingerprint is introduced. By utilizing the solvent-free fingerprint development technique, the truly green and non-toxic fingerprint enhancement technique can be achieved. To accomplish this, the low pressure sublimation prototype system was used and the factors of the prototype system were established in this experiment. According to the experiment results, by turning on the heating source to 160℃ when the pressure is pumped down to 35mTorr and using 100mg of genipin can develop the latent fingerprints. Keywords: Fingerprint enhancement technique, Natural reagent, Low vacuum sublimation, Genipin, Lawsone