亮绿SF溶液增强红色光滑客体表面潜血手印技术研究

目的探索一种实验室和犯罪现场上均可使用的红色光滑表面上血潜手印新型显现技术。方法把0.2g亮绿SF溶解到容积为200m L盛有5m L蒸馏水的烧杯中,然后加入0.2g正四丁基碘化铵、93m L无水乙醇,使用玻璃棒搅拌,充分溶解后,最后加入盐酸2m L形成绿色透明溶液作为显现液,采用精细喷雾器喷涂客体增强红色光滑面潜血手印,潜血手印增强后,照相提取后并对局部放大观察效果,研究其对红色光滑表面潜血手印的增强效果。结果对遗留手印进行了批量显现与统计分析,0.2%的亮绿SF酒精显现液对红色客体表面潜血手印的反应极其敏感,实验室条件下潜血手印样本显现率可达100%,显出的手印纹线清晰连贯,反差明显,无颜色背景,且局部放大能够有效显示出纹线的细节特征。结论 0.2%的亮绿SF显现液能有效增强红色光滑客体表面潜血手印,反差极其明显,可以作为红色光滑客体表面潜血手印增强试剂。     

京尼平序列显现手印方法研究

目的考察京尼平溶液显现手印的灵敏度,并探索DFO→京尼平→茚三酮方法联用显现纸张上潜在手印的效果。方法通过使用京尼平溶液对同一手印样本进行一次、两次和三次浸泡处理,考察浸泡次数是否会影响显现效果;通过对京尼平→茚三酮、茚三酮→京尼平,京尼平→DFO和DFO→京尼平方法的组合设计方案与每种方法的单独使用进行比较研究,考察序列显现方法对显出手印的影响。结果单用京尼平溶液对同一样本进行多次浸泡在自然光和荧光模式下都不会明显增强手印的显现效果,DFO方法先于京尼平、京尼平先于茚三酮使用都能起到增强手印纹线的效果。结论京尼平方法显现手印灵敏度较高,DFO→京尼平→茚三酮方法联用可以进一步提高手印的显出率。     

利用碘胶纸贴附法显现汗潜手印

碘熏显手印法,是现场勘查中显现汗潜手印的方法之一。由于传统的和现有的方法有时受到现场空间的制约,无法兼顾水平面、垂直面、凸凹面以及狭窄处的手印显现。为此,笔者研制了一种安全、快捷、简易、经济、适用于基层使用的操作装置和方法。     

一次手印鉴定引发的思考

近期,我们受理了一起特殊的手印鉴定。此前该手印已有肯定与否定两种截然相反的鉴定结论,鉴定委托人又不能提供检材和样本原件,只将相关的照片送检。在检验过程中,我们经过观察分析、实验验证、计算机图像处理等过程,弄清了手印的本质,做出了科学、客观的结论。     

依据手足印推算身高体重的可行性研究

目的探讨身高、体重与足迹、手印长宽的关系,有助于利用犯罪现场的手印、足迹推断遗留人的身高与体重。方法通过足迹、手印的捺印和测量,大量地收集样本足迹、手印与身高、体重等数据,借助SPSS数理统计软件,进行一元线性回归分析。结果分别建立了由左右足迹、手印全长、掌宽推算身高与体重的十个一元线性回归方程,并对依据左、右侧指标分别推算结果的可靠性进行比较研究。结论可利用回归法由足迹、手印来推算身高、体重。在左右两侧足迹、手印都可利用的情况下,推断身高时应优先选用右侧;推断体重时应优先选用左侧。     

影响指纹自动识别系统运行效益的原因与对策

作者根据自身工作实践,对几年来使用指纹自动识别系统的情况进行了深刻、全面的总结和分析,剖析了制约系统充分发挥作用的一些主、客观因素,并提出了解决问题的对策,以供同行参考。     

浅析现场手印定位对鉴定结论的影响

现场留痕手印通常因作用力及承痕体等外因的影响,出现变形现象,直接影响了检验鉴定结论的准确性。检验鉴定前对现场留痕手印进行全面分析,判定其留痕部位,从而作出准确的鉴定结论。     

Assessing the Risk of Secondary Transfer Via Fingerprint Brush Contamination Using Enhanced Sensitivity DNA Analysis Methods

Experiments were performed to determine the extent of cross‐contamination of DNA resulting from secondary transfer due to fingerprint brushes used on multiple items of evidence. Analysis of both standard and low copy number (LCN) STR was performed. Two different procedures were used to enhance sensitivity, post‐PCR cleanup and increased cycle number. Under standard STR typing procedures, some additional alleles were produced that were not present in the controls or blanks; however, there was insufficient data to include the contaminant donor as a contributor. Inclusion of the contaminant donor did occur for one sample using post‐PCR cleanup. Detection of the contaminant donor occurred for every replicate of the 31 cycle amplifications; however, using LCN interpretation recommendations for consensus profiles, only one sample would include the contaminant donor. Our results indicate that detection of secondary transfer of DNA can occur through fingerprint brush contamination and is enhanced using LCN‐DNA methods.     

The impact of lipid degradation on fingerprint quality on fired firearm cartridges

The recovery of identifiable fingerprints from fired cartridge cases is challenging. Therefore, the characterization of chemical modifications and their effects on fingerprint integrity post-firing is essential. In this study, the primary fingerprint lipids, including myristic acid, pentadecanoic acid, palmitoleic acid, palmitic acid, stearic acid, squalene, and cholesterol in fired and unfired cartridges, were extracted with acetonitrile, followed by derivatization using N,O-Bis(trimethylsilyl)trifluoroacetamide with 1% trimethylchlorosilane (BSTFA/1%TMCS). Squalane was used as the internal standard, and all quantifications were performed using gas chromatography coupled with mass spectrometry using a triple-quadrupole mass filter. All lipids identified in the unfired cartridges were also detected in the fired cartridges, and statistical analysis using Student's t-test and F tests was performed with a 95% confidence level. The concentration of lipids in the unfired cartridges was found to be similar to that detected in the fired cartridges, except for squalene, the recovery of which was 28% lower in the fired cartridges.     

数字化描述指纹鉴定结论的初探

目的 针对指纹鉴定常用的5类纹型所占的概率、4类细节特征点所占的概率及4类细节特征点组合概率,探讨用数字计算出指纹鉴定结论相同概率的方法.方法 取已破案件被比中人员中具有5类纹型及4类细节特征点的指纹1000人份,分为10组,每组100人份进行概率分析.结果 指纹的5类纹型、4类细节特征点及组合概率存在稳定的规律.结论 可以数字化描述指纹鉴定结论.