灰尘车漆表面汗液手印显现方法研究

Research on Developing Method of Sweat Fingermark On Dust Truck Paint

【目的】在涉车类案件的现场勘查中,由于车辆长时间存放在室外,表面落有灰尘,遗留的手印大多是灰尘减层手印,显现难度大幅增加。【方法】选取不同颜色车漆为手印遗留客体,选用410 nm波段光源直接照射、490 nm波段光源直接照射、黑色磁性粉或银粉等常规粉末刷显、黄色荧光磁性粉刷显、黄色荧光磁性粉刷显后用410 nm波段光源照射、黄色荧光粉磁性粉刷显后用490 nm波段光源照射等6种不同的方法显现手印、比较效果。【结果】使用黄色荧光磁性粉刷显配合410nm波段光源照射黑色、银灰色、浅绿色车漆表面的手印,效果最佳;配合490nm波段光源照射银灰色和浅绿色车漆表面的手印,也能取得较理想的效果;白色车漆表面的手印,使用黑色磁性粉刷显效果最佳。【结论】在实战工作中,遗留在带有灰尘的黑色、银灰色、浅绿色等车漆表面的手印,可用黄色荧光磁性粉刷显配合410nm或490nm波段光源照射显现,遗留在带有灰尘的白色车漆表面的手印,可用黑色磁性粉刷显。

[Purpose]During the on-site investigation of vehicle related cases,due to the fact that the vehicle has been stored outdoors for a long time,and there is dust on the surface,most of the remaining fingerprints are dust reduced fingerprints,which greatly increases the difficulty of rendering.[Methods]Different colors of car paint were selected as the remaining objects of the fingerprint.Six different methods were used to develop the fingerprint,including direct irradiation with a 410 nm light source,direct irradiation with a 490 nm light source,conventional powder brushing such as black magnetic powder or silver powder,yellow fluorescent magnetic brushing,irradiation with a 410 nm light source after yellow fluorescent magnetic brushing,and irradiation with a 490 nm light source after yellow fluorescent magnetic brushing.The results were compared.[Results]Using a yellow fluorescent magnetic brush to display fingerprints on the surface of black,silver gray,and light green car paint combined with a 410 nm wavelength light source has the best effect;With a 490 nm wave band light source illuminating the fingerprints on the surface of silver gray and light green car paint,ideal results can also be achieved;Handprints on white car paint surfaces are best displayed using black magnetic paint.[Conclusion]In practical work,fingerprints left on the surface of black,silver gray,light green vehicle paint with dust can be displayed using yellow fluorescent magnetic brush in combination with 410 nm or 490 nm light source irradiation.Handprints left on the surface of white vehicle paint with dust can be displayed using black magnetic brush.