광학적 특성 평가기법을 이용한 지문현출 시약 1,2-IND와 BY40의 광발광 모드 최적조건에 대한 연구

Abstract

Fingerprints are formed on various surfaces in crime scenes. Cyanoacrylate fuming with Basic Yellow 40 is usually used on non-porous surfaces and 1,2-Indanedione is the most common reagent for developing latent fingerprints. In general, developed fingerprints are observed using a light source and filter within corresponding wavelength range. This observation technique is called photoluminescence mode. Since the photoluminescence mode uses light sources and filters in the darkroom, it is easy to observe only the developed fingerprints. Therefore, many studies have been conducted to find best filter and light combination of latent fingerprint development reagents. But most of the studies on optimal photoluminescence conditions were based on visual evaluation methods such as the Home Office Grading System or SWGFAST. Since these visual evaluation criteria are based on the evaluator's visual judgment, the results may vary depending on the evaluator's competency, and it is difficult to compare if the difference in the degree of enhancement and appearance is small. To solve this problem, this study aims to quantify the quality of fingerprints and establish the optimal conditions for fingerprint development reagent(1,2-Indanedione, Basic Yellow 40) commonly used on porous and non-porous surfaces. Evaluation factors were set as optical characteristics that can affect the evaluation of the fingerprint, referring to previous studies. Brightness, contrast, signal to noise ratio were set as evaluation factors. More detailed comparison was possible using the optical characteristic evaluation technique, and the optimal light source and filter conditions according to the reagent could be found.