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161.
162.
Conventional development of latent fingerprints is compromised when the prints are decomposed by extreme temperatures, such as those encountered when a weapon cartridge is fired, an improvised explosive device is detonated, and/or in arson cases. Understanding how these extreme temperatures alter the chemical and physical properties of latent fingerprint residue could aid in the discovery of a reagent that could effectively develop these decomposed fingerprints. To mimic scenarios where fingerprints may be exposed to high heat conditions, standards of the five most abundant amino acids in fingerprint residue as well as extracted fingerprint residue were pyrolized under controlled conditions. Compounds identified as pyrolytic decomposition products were 3,6-dimethylpiperazine-2,5-dione (from alanine), maleimide, and 2,5-furandione (from aspartic acid). The pyrograms and selected ion traces show these products to hold promise as indicators of decomposed fingerprint residues and, therefore, may serve as good candidate substrates for a developing reagent. 相似文献
163.
164.
防止茚三酮溶液扩散纸张字迹的研究 总被引:1,自引:0,他引:1
目的 解决茚三酮溶液在显现手印同时对纸张上字迹产生扩散作的问题;方法 分别采用茚三酮丙酮溶液,茚三酮氟利昂溶液,茚三酮石油谜溶液,茚三酮庚烷溶液作比较。结果 钢笔字迹用4种溶液均不易扩散;纸张上其它成份字迹用后两种方法显现手印时可有效保存纸张上文字原貌。 相似文献
165.
目的创立一种警用多个数字传感器同通道活体指纹采集系统。方法应用多个数字传感器定时同步控制技术、模拟无穷远成像技术、自适应采集参数控制、指位校准、内置专业模糊匹配算法等进行技术创新。结果有效提高活体指纹采集的成功率。结论该系统在实践工作中有广泛应用价值。 相似文献
166.
167.
Development of a GC-MS method for the simultaneous analysis of latent fingerprint components 总被引:1,自引:0,他引:1
Latent fingerprint residue is a complex mixture of organic and inorganic compounds. A full understanding of the composition of this mixture and how it changes after deposition is lacking. Three solvent systems were compared for the simultaneous extraction and derivatization with ethyl chloroformate of selected amino and fatty acids from a nonporous substrate (Mylar for subsequent analysis by gas chromatography-mass spectrometry. A solvent system comprised of sodium hydroxide, ethanol, and pyridine was found to be the most effective. This method was applied to the analysis of latent fingerprint residue deposited on Mylar and preliminary data are presented. Twelve amino acids (e.g., serine, glycine, and aspartic acid) and 10 fatty acids (e.g., tetradecanoic, hexadecanoic, and octadecanoic acids) were identified. The potential application of this method to further the understanding of latent fingerprint chemistry has been demonstrated. 相似文献
168.
Evaluation of Four Fingerprint Development Methods for Touch Chemistry Using Matrix‐Assisted Laser Desorption Ionization/Time‐of‐Flight Mass Spectrometry, 下载免费PDF全文
Kimberly A. Kaplan‐Sandquist Ph.D. Marc A. LeBeau Ph.D. Mark L. Miller Ph.D. 《Journal of forensic sciences》2015,60(3):611-618
Four preparation techniques for MALDI/TOF mass spectrometry were compared to determine the ability to gather intelligence for investigations through the chemical analysis of latent fingerprints, defined as “touch chemistry.” Compatible fingerprint development processes used for identification along with new techniques are necessary to evaluate touch chemistry. Ten volunteers deposited fingerprints from solvent residues containing drugs and explosives onto microscope slides. The developers included (A) fingerprint powder, (B) MALDI matrix, (C) fingerprint powder and lifting, and (D) cyanoacrylate fuming with fingerprint powder. Qualitative identification was based on ion images and spectra. The highest average detection rates (88%) were found using methods A and B. Methods C (52%) or D (18%) had limited success. Results demonstrate the importance of imaging coupled to extracted mass spectral data in detecting analytes in deposited fingerprints. Overall, the results suggest continued development of touch chemistry applications could prove useful for gathering intelligence and forensically relevant information. 相似文献
169.
本文主要论述了新型指印荧光显现剂的基本原理、配方和实验结果.所配制的显现剂可显现牛皮纸、白纸、铜板纸、明信片等纸张上的指印,也可以显现塑料、油漆面、原木、乳胶漆墙面等客体表面的指印,使用方便、快捷. 相似文献
170.
中国法庭科学DNA数据库 总被引:9,自引:4,他引:5
本文综述了中国法庭科学DNA数据库的建立和发展过程、DNA数据库结构、内容、特点、作用以及存在的问题、发展方向、展望,目的是为如何进一步建设好具有中国特色的DNA数据库提供借鉴。 相似文献