An Experimental Research On The Sequencing Under Macroscopical Non-crossing Condition

In the practice of forensic science, cases involving laser printings increased year by year. Document examiners often encounter cases of identifying the sequencing of laser printings and seals under non-crossing condition. Traditional identification methods of Zhumo sequencing can’t handle such complicated questions as this, thus it makes the examination on the sequencing of laser printings and seals under non-crossing condition one of the biggest difficulties in the area of questioned documents examination. Therefore, it’s time for us to make an innovation.At present,material related to the research on Zhumo sequencing is seldom in our country and hardly any work has ever discussed about it in a systematical and specialized way. In fact, the experts and scholars always pay much attention to the examination on sequencing of laser printings and handwritings under macroscopical non-crossing condition. Even though the object mentioned above is different from the one in this research, its method has given the author a great deal of enlightenment and could also be a good reference to this paper.This experiment is divided into four stages. The first stage illustrates the theoretical basis of examination on the sequencing of laser printings and seals, which 2is the premise of this experiment. At this stage, the author makes definitions on relevant objects of identification of laser printings and seals under microscopical non-crossing condition and also explains relevant principles and methods of this experiment. The second stage discusses about the experimental research on the characteristic changes and regular patterns of the Zhumo sequencing. The methods mainly used here were the 2D examining method and the 3D examining method. The 2D examining method begins with the residual powdered ink of the cross-site, observing both the residual probability and the distribution situation of the residual. The 3D examining method starts with the cross-site of printings and seals, observing the characteristics and the 3D depth of the cross-site. The third stage discusses about the influencing factors of the experiment after the systematical analysis on the recording data and also the summary on the specializations, differences and regular patterns of the characteristics shown under different sequencings. The last stage restates some relevant key points and notes through the examination of a typical case in this field, and puts forward some practical methods to this problem.The experimental study finds that the hierarchical relationship between powdered ink of the laser printer and the pigment of seals is an important characteristic with which we can use to identify the sequencing of the laser printings and seals under macroscopical non-crossing condition. In the samples of water-based ink-pad seals and photosensitive seals where printings lie above stamps, powdered ink particles suspend on the pigment of stamps, and the powdered ink particles are glossy and have a strong three-dimensional sense. However, in the samples of water-based ink-pad seal stamps and photosensitive seal stamps where stamps lie above printings, powdered ink particles are covered by the pigment of the stamps. The powdered ink particles are have neither gloss nor three-dimensional sense. But the characteristics of this cross-site couldn’t reflect the sequencing of laser printings and ink-pad seals or atomic seals. At this point,the 3D morphological characteristics of the stamps is an important reference to the examination on the sequencing of the laser printings and seals under macroscopical non-crossing condition. In the samples of the photosensitive seals where printings lies above stamps, the stamps can retain a microcosmic characteristics and reflect in a 3D model. In the samples of the photosensitive seals where stamps lie above printings, the stamps are extruded. This experiment also find that time is a strong influencing factor when examination the sequencing of laser printings and seals under macroscopical non-crossing condition.The result of this experimental research contains two parts. Part one summarizes the characteristics and regular patterns of the sequencing and utilizes the characteristics here to make a comparatively accurate determination on whether the sequencing of files is normal or not. Part two shows a conclusion on the influencing factors and cautions during the process of this whole experiment, hoping to avoid errors afterwards.