卫生纸上汗潜手印显现方法比较研究

Comparison between Approaches to Develop Sweat Latent Fingerprints on Common Toilet Paper

目的通过比较实验来探寻卫生纸上汗潜手印的最佳显现方法,为实际工作提供指导性建议。方法选择市面上常见的四种卫生纸,在每种卫生纸上制作汗潜指印实验样本,分别将茚三酮溶液浸泡法与茚二酮溶液浸泡法、茚二酮溶液浸泡法与茚二酮溶液超声雾化法、茚二酮溶液超声雾化法与(对)-二甲(替)氨基肉桂醛(DMAC)显现纸冷熏法、茚二酮溶液浸泡法与红外加热显现法、茚二酮溶液超声雾化后加热显现法与室温显现法进行两两比较,分析显现效果。结果茚二酮显现的灵敏度和质量均优于其他几种方法,特别是超声雾化后室温显现,既能很好地显现手印又不影响后期的DNA检验。结论采取茚二酮超声雾化室温条件显现方法显现卫生纸上的汗潜手印具有显现效果好、设备条件要求低、操作性强的特点,在实际案件中可以借鉴应用。

Objective To explore the suitable approach about developing sweat latent fingerprint on toilet paper through comparative experiments with purpose to provide reference for practical work.Methods Four commonly market-available types of toilet paper were chosen for the sweat latent fingerprint to deposit on each of them.Every piece of the above-made fingerprint sample was cut into two parts where different treatments were respectively handled to make the latent fingerprint visualized and compared.The pairwise handling treatments were planned as follows:ninhydrin solution soaking against the indanedione’s(IDO’s);IDO solution soaking against ultrasonic-atomized IDO vapor immersing;ultrasonic-atomized IDO vapor immersing against DMAC(dimethylaminocinnamaldehyde)paper exposing under room temperature;ultrasonicatomized IDO vapor immersing against infrared heating;ultrasonic-atomized IDO vapor immersing added of heating plus humidifying or none(room temperature).Results The sensitivity of IDO treatment was significantly higher than that of the other approaches,especially the ultrasonic-atomized IDO vapor immersing(at room temperature)unveiling the clear fingerprints with the harboring DNA undamaged.Conclusions The approach of ultrasonic-atomized IDO vapor immersing(at room temperature)is characteristic of good visualization of fingerprint,low requirements of equipment and strong operability,capable of being used in practical cases.