管子钳破坏圆柱形客体形成的痕迹及应用

管子钳的结构比较特殊 ,其成痕原理、受力情况及痕迹特征都不同于一般的钳类或扳手类工具。管子钳破坏圆柱形客体形成的痕迹 ,通常是线条状痕迹伴随凹陷状痕迹同时出现。其痕迹特征可用来分析作案工具种类与规格、作案人职业特点等 ,也可用来进行比对检验 ,确定作案工具     

车辆痕迹在侦破盗窃案件中的应用

文章探讨了侦破盗窃案件过程中如何寻找、确定现场车辆痕迹,需要测量、提取的车辆痕迹种类以及在侦破盗窃案件中对车辆轮胎印痕、车体痕迹,整体分离物痕迹、微量物证的具体应用。     

浅谈Photoshop在痕迹检验中的应用

Photoshop是Adobe公司生产的一款功能强大的图像处理软件。它集图像制作、编辑修改、图像合成及影像输出等于一体。由于其强大的适用功能与可操作性,已经成为众多平面设计、图形、图象处理者的首选软件。公安机关的刑事技术人员,将其应用于刑事技术的痕迹检验中,可以发挥重要作用。     

线条状痕迹在推断工具种类中的应用

线条状痕迹是以凹凸起伏的线条反映工具上的特征的,并且凹凸象相反。工具与物体存在相对位移时,工具上凸起的部位能够形成凹陷的线条、工具上凹陷的部位能够形成凸起的线条。工具表面上的线条状加工花纹,通过压力作用,可以印压在物体表面上并形成线条状痕迹反映。根据线条状痕迹的具体情况,能够在一定程度上推断出形成痕迹的工具种类。     

谈鞋底整体分离痕迹的形成与应用

鞋底整体分离痕迹的检验是刑事技术领域所研究的课题之一。不同种类的鞋底分离形成的鞋底分离痕迹各不相同,这就要求基层刑事技术人员在勘验现场时认真发现、提取、保存分离痕迹,根据痕迹的种类,形成原因、特征等进行比对检验,为刑侦工作服务。     

锯痕检验的方法

根据锯痕的特征对锯痕和嫌疑人进行分析,并利用伤、缺齿痕、歪齿痕、被折断的锯痕,以及断面附着物等痕迹特征,对嫌疑锯进行鉴定的方法对于锯痕检验十分具有现实意义。     

Detection of Contact Traces of Powdery Substances

The current practice in securing the contact traces of chemical substances taken from clothes belonging to a person suspected of manual handling explosives is focused on pockets and cuffs. The outerwear worn by people who had contact with fluorescent powders that simulate explosives and drugs was the subject of this study. Clothes were first exposed to the test substance for a period of time and then analyzed by fluorescence methods to determine the location of the highest quantity of traces. The results obtained from the study confirm that the areas with the highest concentration of powdery traces are different from those suggested by current forensic practice. They appear to be promising for a more efficient identification of the suspects involved in illegal manufacturing of drugs of abuse or explosives. Moreover, they may be helpful for developing the methodology for handling the evidence material in the forensic clothing examination process.     

Transfer of Triazine‐iron(II) Chromic Complexes Left by Iron Items on Textile Background and Human Skin

Abstract: The research is focused on the detection and transfer of iron traces left by iron items on clothing and human skin. The method is based on the formation of colored complexes between ferrous ions and five synthesized, mostly new triazines. Iron traces originally were left by iron rings on slightly wetted (artificial sweat) cotton fabrics and subsequently transferred to a separate textile substrate. Prior to the use of trazines the contact spots were treated with a new inorganic reducing agent (Sn²⁺) to reduce Fe³⁺ to Fe²⁺. The method is sensitive to detect iron traces on wetted canvas after 10 min contact with iron items. More spectacular results were obtained for traces left on human palm even after very short contact (10 sec). The new iron‐trace‐transfer method eliminated the contact of triazines solutions with human skin. Transmission visible spectra of Fe(II)–triazine complexes were determined.     

Analyzing Forensic Evidence Based on Density with Magnetic Levitation

This paper describes a method for determining the density of contact trace objects with magnetic levitation (MagLev). MagLev measurements accurately determine the density (±0.0002 g/cm³) of a diamagnetic object and are compatible with objects that are nonuniform in shape and size. The MagLev device (composed of two permanent magnets with like poles facing) and the method described provide a means of accurately determining the density of trace objects. This method is inexpensive, rapid, and verifiable and provides numerical values—independent of the specific apparatus or analyst—that correspond to the absolute density of the sample that may be entered into a searchable database. We discuss the feasibility of MagLev as a possible means of characterizing forensic‐related evidence and demonstrate the ability of MagLev to (i) determine the density of samples of glitter and gunpowder, (ii) separate glitter particles of different densities, and (iii) determine the density of a glitter sample that was removed from a complex sample matrix.     

Correlation between saw blade width and kerf width

Most studies of saw marks have focused on morphological characteristics and their utility in identifying saws suspected to have been utilized in cases of criminal dismemberment. The present study examined the extent to which metric analysis may be used to correlate saw blade measurements with minimum kerf widths (MKWs). A sample of 56 partially defleshed white‐tailed deer (Odocoileus virginianus) long bones was utilized as proxy for human remains. The long bones were cut using a variety of commercially available saws, including 11 manual‐powered and 5 mechanical‐powered saws. A total of 496 false start kerfs (FSKs) were created. Two experiments were performed, with the first test examining the MKWs of FSKs produced on specimens that were restrained using a bench vise, while the second test analyzed the MKWs of FSKs produced on minimally restrained specimens. Statistical analysis using Hierarchical Linear Modeling (HLM) indicated a positive relationship between saw blade width (mm) and MKW, with blade width (p < 0.001) and the overall difference between the mechanical‐ and manual‐powered saws (p = 0.029) tested, reaching statistical significance. A comparison of MKWs produced using manual‐powered saws on restrained and minimally restrained bones suggests that restraint condition (p = 0.009) has a statistically significant effect. In comparisons of MKWs to blade widths, the average ratio for mechanical‐powered saws is 18.7% greater than the average ratio for manual‐powered saws. While the mode of the ratios was 1.42, thus supporting the general rule that MKW does not exceed 1.5 times blade width, multiple individual ratios did surpass 1.5.