使用硝酸银和LED区分纸箱上的新旧指纹

Using Silver Nitrate and LED to Distinguish between Fresh and Old Fingerprints on Carton Box

使用硝酸银水溶液,选用合适的LED光源,严格控制光强,在纸箱上进行的指纹显现实验结果表明：不论是人工指纹还是自然指纹,淡的新指纹（4~6小时）总是在浓的旧指纹（3天）之前出现,即该方法可以作为＂新旧指纹差异化显现技术＂中的一种,有望为解决一些复杂案件提供技术支持。同时使用了传统的茚三酮方法进行实验,结果表明新旧指纹的出现是无序的。

The silver nitrate aqueous solution, appropriate LED light source and strict control light intensity were tested to detect fingerprints on carton box. The experimental result indicates that, whether artificial fingerprints or natural fingerprints, light fresh fingerprints（4~6 h） always appear before dense old fingerprints（3 days）. This method could be one of technologies to distinguish between fresh and old fingerprints, and could be used to solve complex judicial cases. At the same time, conventional ninhydrin is useless.