2,4,6-Tri(2′-pyridyl)-1,3,5-triazine for determination of iron(II), Iron(III), and total iron contents on human palms

When iron-based tools, such as knives or guns, are held, traces of iron can transfer to the skin. However, no previous studies have been published regarding the effect of the elapsed contact time on the transfer of iron species with different valences to the palm. Compared with 3-(2-pyridyl)-5,6-diphenyl-1,2,4-triazine (PDT), 2,4,6-tri(2′-pyridyl)-1,3,5-triazine (TPTZ) was found to exhibit a higher sensitivity to iron(II) spectrophotometrically. This work employed 2,4,6-tri(2′-pyridyl)-1,3,5-triazine (TPTZ) and UV spectrophotometry to determine the amounts of iron(II), iron(III), and total iron transferred to human palms from iron tools. It was found that the palmar moisture level was an important factor in determining the amounts of total iron, including iron(II), transferred to the palm. For identical contact times, the amounts of total iron transferred to the palm was proportional to the palmar moisture, and the difference between the maximum and minimum amounts was 12 μg per hand. However, the amounts of iron(II) transferred to the palm gradually decreased over time for low palmar moisture levels, but steadily increased over time for high palmar moisture levels. Additionally, for average levels of palm moisture, the amounts of iron(II) and iron(III) transferred to the palm gradually decreased and increased, respectively, with longer contact times. Notably, this research could serve as a theoretical basis and guide for the detection of trace iron species with different valences on human palms for criminal investigations.     

ID‐Check: Online Concealed Information Test Reveals True Identity

The Internet has already changed people's lives considerably and is likely to drastically change forensic research. We developed a web‐based test to reveal concealed autobiographical information. Initial studies identified a number of conditions that affect diagnostic efficiency. By combining these moderators, this study investigated the full potential of the online ID‐check. Participants (n = 101) tried to hide their identity and claimed a false identity in a reaction time‐based Concealed Information Test. Half of the participants were presented with personal details (e.g., first name, last name, birthday), whereas the others only saw irrelevant details. Results showed that participants′ true identity could be detected with high accuracy (AUC = 0.98; overall accuracy: 86–94%). Online memory detection can reliably and validly detect whether someone is hiding their true identity. This suggests that online memory detection might become a valuable tool for forensic applications.     

Improving Luminol Blood Detection in Forensics

The aim of this study was to develop chemical improvements to the original Weber protocol, in order to increase the intensity and time length of light emission and to eliminate false‐positive reactions. The intensity and duration of light were measured on serial blood dilutions using a plate reader chemiluminometer. Blood stains of various concentrations were impregnated in pure cellulose, dried, and luminol solution was added with/without the potential enhancers. An in silico study was also conducted, aiming to demonstrate the enhancing mechanism of hemoglobin denaturation using 8 M urea. The luminol blood detection test revealed important improvements after urea pretreatment or in the presence of monochloro‐triazinyl‐β‐cyclodextrin. This approach also eliminated the false‐positive reaction from sodium hypochlorite. These improvements could provide a higher sensitivity under particular circumstances such as old or washed blood stains, leading to a better localization for further DNA typing and higher quality photographic analysis.     

人隐瞒信息状态下多通道事件相关电位的研究

目的采用隐瞒信息测试(concealed informationtest,CIT)模式和多通道事件相关电位(event related potential,ERP)技术,对人类大脑在不同刺激下各脑区域活动情况和活跃程度进行对比,从神经电生理学层面揭示CIT模式隐瞒信息状态下视觉刺激人类大脑认知相关脑功能区特征。方法参考犯罪知情测试模式(GKT)的CIT模式,选用传统扑克牌,对17名被试人员进行视觉刺激,包括:靶、探测、无关和中立刺激,获得29通道ERP波。结果靶、探测和无关刺激平均按键反应时间:775ms、774ms和720ms;探测和无关刺激各通道P300峰潜伏期配对t检验,有统计学意义(P0.05)的通道有4个;探测和无关刺激各通道P300平均波幅(400~700ms)进行配对t检验,有统计学意义(P0.05)的通道有19个。结论隐瞒知晓信息是一个由多个脑功能皮质共同完成的复杂过程,与诚实反应抑制有密切关系,与额叶前部和上部皮质、前扣带回皮质(ACC)和缘上回等脑功能皮质特异相关。     

六色荧光标记快速PCR扩增体系的建立及验证

目的建立PCR快速扩增程序和体系,并对其技术指标进行验证。方法采用六色荧光标记技术,对24个常染色体STR基因座、1个Y-STR基因座和Amelogenin、Y-In Del基因座进行复合扩增及毛细管电泳检测,同时考察体系的灵敏度、特异性、同一性、稳定性、混合样本及批量样本测试,并观察各种常见检材及降解、脱落细胞检材的分型情况。结果所建立的体系灵敏度达0.062 5 ng,快速扩增仅耗时65 min就可获得准确分型;种属特异性高;各种纸质血样本和混合、降解、脱落细胞检材的分型正确。结论本研究建立的快速扩增体系可显著提升检验速率,分型准确、稳定,对建立STR数据库、研究群体遗传学和进行法医学鉴定有重要意义。     

论我国少数民族地区的犯罪矫正

我国复杂的民族状况决定了对我国少数民族地区犯罪进行矫正的特殊性及难度,对于少数民族地区的犯罪矫正既要考虑到国家法律的一元性,也要考虑到民族民间文化为犯罪矫正提供的多元化进路。不论是精神性矫正模式、社区性矫正模式还是正式性矫正模式,都需要针对少数民族同胞设计具有民族特点的犯罪矫正机制,使犯罪矫正工作在我国的少数民族地区获得更高的质量。     

爆炸案件现场重建初探

随着国际恐怖主义活动的日益猖獗,爆炸案件也呈逐年上升之势,爆炸案件向来是公安机关重点打击的刑事犯罪之一,因此爆炸案件的侦破工作显得尤为重要。而现场重建运用于现场破坏严重、现场范围大且难度天的爆炸案件现场勘查中有其独特的优势。分析爆炸案件特点、爆炸现场重建要解决的问题,探讨采集现场重建各要素的方式,整合刑事技术方面的多重信息,针对爆炸现场最大限度地提出重建与恢复的步骤、方法,从而使现场重建在爆炸案件侦破工作中发挥其重要作用。     

侦查权的性质及配置模式研究

关于侦查权的性质定位,在我国学界存在行政权说、司法权说、行政权和司法权双重性质说。侦查权作为警察权的一部分,应该是一种行政权。侦查权作为一种重要的国家行政权,在行使过程中存在着两种不同的利益需要,即确保侦查效率与保障人权。科学、合理的侦查权配置,能够确保国家权力得以实现、公民权利得以保障。     

谈目标轨迹在侦查思维中的应用

目标轨迹,是指与刑事案件相关的物证和信息,依据发生的时间顺序,建立方向性的连接,构成点与射线组成的图形。目标轨迹能够将事物的过去、现在和将来联系起来,是侦查思维的外化和表现,它通过对犯罪嫌疑人实施犯罪阶段前后的活动情况进行分析、研究,有助干侦查人员把握侦查的主动权,提高侦查工作效能。文章从侦查思维的角度出发,阐释了目标轨迹在侦查工作中的价值、作用和意义。     

视频侦查规范化研究

视频侦查是指侦查机关根据案件的需要,通过视频监控资料的调取、观看、分析和应用四个环节,实现对犯罪的动态分析和综合判断,以发现和确定犯罪嫌疑人、寻找破案线索,为案件侦查提供方向的一种侦查措施。视频侦查已成为继刑事技术、行动技术、网侦技术之后侦查破案的技术支撑和新的破案增长点,成为强化社会治安控制的有效手段,对提高侦查机关打击犯罪的效能具有重大意义。