基于短波紫外线配光检验技术的潜在指印提取及可视化分析研究

Research on Latent Fingermarks Extraction and Visual Analysis by Short-Wave Ultraviolet Light Distribution Inspection Technique

目的指印是犯罪现场重要物证之一,现场指印的发现和提取是刑事技术人员研究的重要内容。通常现场指印会在各类复杂背景上出现,对其进行提取需要专业技术手段,具有一定挑战性。基于短波紫外线配光检验技术研究不同背景上各类潜在指印的提取方法,并结合自定义评价标准对其进行可视化分析,为潜在指印的提取和评价提供方法参考。方法选用案发现场常见的12种物体表面作为承痕客体,以汗液、油脂、油汗混合、潜血、灰尘减层、灰尘加层等6类指印为研究对象,利用254 nm短波紫外线反射照相对72份样品做配光检验,并系统分析潜在指印增强效果的影响因素,同时建立评价标准。结果试验表明,短波紫外线配光检验照相方法对不同承痕客体、不同指印均有效果,指印反差因客体对光的吸收差异而不同,就此提出的可视化评价标准客观明了。结论试验结果丰富了特种光配光检验技术提取指印的方法体系,为现场此类指印提取和评价提供了参考。

Objective Fingerprint is an important content of crime scene evidence.Criminal technical personnel on-site detection and extraction of fingerprint is an important content of research.Because the scene fingerprints often appear on the complex background,nondestructive extraction need professional technology.Based on the short wave ultraviolet light distribution test technology research on the complex background of various kinds of potential fingerprint extraction method,combined with the self-defined evaluation criteria,the visual analysis is carried out to provide a reference for the extraction and evaluation of latent fingerprints.Methods Twelve kinds of common objects at the crime scene were selected as trace carriers,and six types of fingerprints,namely sweat,oil,oil-sweat mixture,occult blood,dust layer reduction,and dust layer addition,were used as the inspection materials.Seventy-two samples were examined by 254nm shortwave ultraviolet reflectography based on the light distribution test technology.The influencing factors of potential fingerprint enhancement effect were systematically analyzed,and the evaluation criteria were established.Results The experimental results show that for different objects,the short-wave ultraviolet special light distribution test has the extraction effect on different trace carriers and different fingerprint,and the fingerprint contrast is different due to the light absorption difference of the objects.Conclusion The experimental enrich the method system of fingerprint extraction by light distribution inspection technology and provide a reference for the extraction and evaluation of such fingerprints on site.