25 June 2015, Volume 40 Issue 3
    

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  • Advances in the Application of ICP-MS in Bullet Identification
    SONG Xiaojiao, GUO Hongling, MEI Hongcheng, QUAN Yangke
    Forensic Science And Technology. 2015, 40(3): 173-178. https://doi.org/10.16467/j.1008-3650.2015.03.001
    Abstract ( ) Download PDF HTML   Knowledge map Save
    In shooting cases, bullets are very important physical evidence. To link a bullet that has been fired to a certain weapon, the most conclusive way is still by identifying the striation marks on bullet. However, quite often in casework, the marks comparison cannot be carried out. For example, the firearm is covered or the bullet is totally crushed, and only bullet fragments or particles remain in victims’ body or at the crime scene. In such circumstances, chemical analysis of bullet fragments or lead particles can play a pivotal role in helping to identify the source of the bullet. Usually, three kinds of chemistry comparisons can provide useful information: lead isotope ratios, the percentage of antimony and amounts of trace elements. Lead has four stable isotopes, namely 204Pb, 206Pb, 207Pb and 208Pb. The 204Pb has no radioactive precursor, while the other three come from nuclear disintegration of 238U, 235U and 232Th, respectively. The isotopic ratios of lead in bullets vary as a function of the age of the ore field where lead was extracted, so isotopic composition analysis is reliable to distinguish the source of bullets. Antimony is added by manufacturers in different proportions to harden the bullet depending on the characteristics needed. Analysis of antimony content would contribute to confirm the results obtained with the lead isotopic ratios measurement. The amounts of trace elements are relevant to lead origin and its manufacturing process, so determination of minor and trace metals in bullets might give additional information. Inductively coupled plasma mass spectrometry (ICP-MS) can provide both multi-elemental and isotopic information, which makes it become a very appealing technique in forensic science. For example, the technique shows the potential to be able to identify bullets in criminal investigation. Since the first work which based on analyzing elemental and isotopic properties of bullets through ICP-MS instrument was published by Dufosse and Touron, more and more forensic scientists have been paying close attention to this topic. In this paper, the principle and category of ICP-MS technique is outlined, and the previous literatures in relation to the continuing and developing use of ICP-MS in identifying bullets are reviewed. At last, the reasons of few studies on ICP-MS method for the determination of chemical properties of bullets had been done by Chinese forensic scientists are also analyzed. Determining the chemical properties of bullets, especially lead isotope ratios in bullets, and establishing database for the bullets made in China, will be very helpful to identify the sources of bullets.
  • Time Since Discharge of Chinese-made Cartridges
    BAO Liyin, ZHOU Zhifei, LI Yiyi, WANG Xiaolin, ZHANG Gang, MA Xinhe, WANG Guiqiang
    Forensic Science And Technology. 2015, 40(3): 179-183. https://doi.org/10.16467/j.1008-3650.2015.03.002
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    Objective The time lapse of spent cartridge usually plays an important part in gunshot crime investigation. This study conducted quantificational analysis of volatile nitrate organics for estimation of the discharge time of Chinese-made cartridges. Methods Volatile nitrate organic products on the internal of fired cartridge cases, shotgun shells and gun barrels diffused into air slowly with time. After shooting, 7.62 mm model 51 pistol cartridges and 12/70 JIALING shotgun shells were sampled with solid phase micro-extraction (SPME) since discharge from day 1 and day 9, and analyzed by gas chromatography-thermal energy analyzer GC-TEA in order to detect the volatile nitrate organic of gunshot residues. Results One notable double peak detected from fired 12/70 JIALING shotgun shells was observed in GC-TEA chromatogram. The observed double peak became weaker along with the increasing time since discharge, and it became too weak to be identified on day 11. Not only the existence of volatile nitrate organic compounds but also the decrease of its amount was indicated in the analysis. However, the similar double peak of volatile nitrate organic compounds, observed in 12/70 JIALING shotgun shells, was not existent at all in 7.62 mm model 51 pistol cartridges. The content of volatile nitrate organics, generated during shooting, was not enough for GC-TEA test.Conclusions For the first time, the variety curves of the volatile nitrate organic compound content and the time since discharge of cartridges made in China was obtained. The test method of GC-TEA could be used in the discharge time estimation of the 12/70 JIALING shotgun shells, but not in that of the 7.62 mm model 51 pistol cartridges. For different types of cartridge, the concentration of volatile nitrate organic compound extracted from the shell has to be detectable with SPME-GC-TEA, prior to estimating the time since cartridge discharge.
  • Shooting Distance Estimation of Model 64 Pistol by Modified Griess Test
    LI Qian, WEN Jinfeng, PENG Cong, WANG Zhaohui, HUANG Wei, LIN Xianwen, DAI Weilie, XING Ruokui, Hu Sunlin, WANG SongCai
    Forensic Science And Technology. 2015, 40(3): 184-188. https://doi.org/10.16467/j.1008-3650.2015.03.003
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    Objective To estimate the shooting distance of model 64 pistol by visualizing the patterns of nitrous compound in gunshot residues (GSRs) using modified Griess test (MGT). Methods A series of GSR samples by shooting against a target of PU cloth (30 cm×20 cm) at muzzle-to-target distances of 0, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 60, 80, 100, 120, 140, 170, 200, 300, 500 and 1000 cm were analyzed. A new device had been made, so that the shooting samples could react with photographic paper treated with modified Griess reagent in acetic vapor. The orange spots in photos exhibited the location of gunshot residue containing nitrite, and stood for the distribution of nitrites. The coloring process was optimized on such aspects of reaction device, reacting temperature, reacting time and photographic paper. The test was carried out as following: first, the reacting tray with 30% acetum was heated to 80℃ for 3 min, then a piece of printing photographic paper was treated with modified Griess reagent for 1 min, dried for 1 min, and was reserved between two printing papers. The reaction took place for 5 min with the stack on coloring plate which had the filter paper with the gunshot sample, the processed photographic paper, the gauze, the sponge on top; lastly, took picture of the reacted photographic paper. The chroma at -30 and saturation at 70 were set in Photoshop. Results A photo-bank of color spot distribution related to shooting distance was built up from this gunshot sample collected at distances within 0~1000 cm. The images of 0, 2 and 5 cm samples were briefly color lumped and the color lump area increased with the distance. Above 2 cm, the radius of color lump distribution increased distinctly, and the color spots exhibited the trend of denseness to thinness. The samples within 100 cm revealed the discriminating color spot distribution with each other while the color spot differences were inconspicuous over 100 cm distance. There were almost no color spots visible beyond the distance of 200 cm. Conclusions The color spots developed with the method are definite, stable and repeatable. Using this approach, it is possible to accurately estimate the firing distance from the target.
  • Standardization of Firearm Property Examination
    LV Xiaosen, LIU Ying, YU Aoyang, SHEN Yuntao, WANG Lu
    Forensic Science And Technology. 2015, 40(3): 189-192. https://doi.org/10.16467/j.1008-3650.2015.03.004
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    Firearm evidence is usually encountered in crimes against persons, and firearm identification often poses a challenge towards examiners. Over the last few years, being the fundamentals in the legal landscape, examination and identification of firearm have drawn more and more attention. The main objective of this study is to develop reliable criteria to identify firearm property by the review of the status and common testing methods, and discussion of the difficulties encountered in firearms identification. The latest methods, conventional methods and practical situation have been integrated. Performances, material, shape and reliability of suspected firearms, as well as the standard classification of firearms should be taken into consideration in standardization of firearm examination. It’s expected that a viable, scientific and efficient standardized mode of firearms examination would be established.
    • Research Articles
  • Victimology in Homicide Crime Scene Analysis(Part II)
    MIN Jianxiong
    Forensic Science And Technology. 2015, 40(3): 193-195. https://doi.org/10.16467/j.1008-3650.2015.03.005
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    As the second part of the serial treatise titling victimology in homicide crime scene analysis, this paper mainly focuses on the association and/or relationship between the individual identity of victim and the homicidal scene based on the three aspects namely occupation, age and gender, revealing the relevant assistance in perusing the involved scenes. With the given examples, the occupation of taxi-driver and sex-worker is of comparatively higher probability to render the practitioners to be killed; children including the newborns and infants together with the elders are liable to be murdered in association with the factor of age; and the transsexuals, when involved into sex activity, can provide worthwhile clues for investigation with their peculiarities of both themselves and the crime scenes although ordinary cases linking with natural genders are difficult to determine the relationship with either the motives to commit crimes or the identities of the criminals.
  • An Exploratory Study Assessing Cognitive Function in Alcohol-dependent Patients
    RUAN Ruoyun, XIONG Hui, GUO Run, LU Xiang, CHEN Fan, YE Yi, YAN Youyi, LIAO Linchuan
    Forensic Science And Technology. 2015, 40(3): 196-198. https://doi.org/10.16467/j.1008-3650.2015.03.006
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    Objective To assess cognitive function in patients with alcohol dependence syndrome to provide a foundation of clinical diagnosis and treatment for such kind of disease and offer a reference for evaluating whether alcohol-dependent patients are able to take responsibility, either full or partial. Methods 27 patients with alcohol dependence syndrome were chosen and received two tests of visual choice reaction time and cancellation efficiency before and after treatment, respectively. 30 healthy volunteers, whose gender, age and education background were matched with the patients, were selected as the control group and received the above same two tests before and after drinking alcohol but with the latter being conducted when no signs of ethanol and acetaldehyde showing in the subject’s blood. Finally the data were processed with the analysis of variance. Results Compared with the control group, the patients of alcohol dependence syndrome had statistically significant difference in the two tests either pre- or post- treatment (P<0.01). There were also significant changes for the patients of alcohol dependence syndrome between pre- and post- treatment (P<0.05) whereas none for the healthy volunteers before and after drinking (P>0.05). Conclusions Part of the cognitive function of alcohol-dependent patients is damaged irreversibly no matter whether treatment has been made or not.
  • A Preliminary Evaluation of DNA Evidence in Criminal Investigations Based on National DNA Database
    LIU Bing
    Forensic Science And Technology. 2015, 40(3): 199-203. https://doi.org/10.16467/j.1008-3650.2015.03.007
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    For the last decade, China national DNA database has expanded exponentially, and held tens of millions of data, including not only the DNA profiles, but also a large amount of relevant information, related to crime scenes, evidence, individuals, etc. This paper attempts to evaluate the function of DNA evidence and DNA analysis in criminal investigations. Data in the national DNA database uploaded from 2011 to 2014 was selected, and a systematic analysis is carried out on multiple dimensions, such as time, evidence type, crime type, match rate, etc. As expected, DNA analysis has an outstanding performance in criminal investigations either in case solving or crime linking with the effective utilization rate close to 50%. It emerges as a powerful tool in criminal investigations, especially in rape cases with matching rate of evidence (MRe) of 71.1%, and murder case at 62.1% of matching rate. The DNA evidence also plays significant role in fighting against professional crimes from 2011 to 2014, in which the evidence for theft and drug cases rises to 124%, 477.3%, and the match number up to 55.3%, 378.6%, respectively. By the systematic analysis of the practical value of common biological evidence, it reveals that traditional biological sample, like blood, semen and saliva (including cigarette butt), covers 82.8% of all the samples detected in DNA laboratories, while new types of samples are becoming more popular. During the same period of time, the number of touch DNA evidence has a growth of 241.7% in total and the match number rises to 158.5%. This paper also proposes that the key evidence should be carefully collected according to the specific type of crime scene to make sure that the evidence won’t be compromised in the following investigation and litigation.
  • Determination of Safrole by Ultra Performance Liquid Chromatography
    ZHAI Wanfeng, LI Peng, HE Jianfeng, GAO Lisheng
    Forensic Science And Technology. 2015, 40(3): 204-207. https://doi.org/10.16467/j.1008-3650.2015.03.008
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    To establish a quantitative method for determination of safrole by ultra performance liquid chromatography (UPLC), safrole samples were diluted by methanol, oscillated with the speed of 1500r/min for 10 minutes or ultrasound-assisted oscillated for 3 minutes, then filtered the solution with 0.22 µm membrane and drew 1.5 mL for automatic injection. The separation was optimized and performed on a Shimadzu ODS-SP column (250 mm×4.6 mm, 5 µm). The mobile phase was pure water (A)-acetonitrile (B) and the mode of elution was gradient. The initial condition was 60%B, and the gradient steepness of organic phase was 0.5%/min between 0~13 min, then the organic phase’s content was raised to 95% immediately and held on for 7 minutes. The complete gradient elution procedure was 60%B (0.01 min)~66.5% B (13 min)~95%B (13.01 min)~95% B (20 min). Flow rate was set as 1 mL/min, column temperature was set as 40℃ and injection volume was set as 5 μL. The primary quantitative wavelength of UV detector was set as 210 nm and the auxiliary one was set as 235 nm. When the organic phase’s initial content increased, theoretical plate number and retention time decreased, but peak height increased. When the gradient steepness increased, theoretical plate number and peak height increased, but retention time decreased. Using the optimized method, good linearity was achieved over the range of 2~200 μg/mL. External standard working curve Y=1833.39X+5675.32, r2>0.9999. Limit of detection was 0.1 μg/mL under the condition of S/N>3. The precision was good with the intra-day RSDs less than 1.26% and inter-day RSDs less than 2.08%. The accuracy was also satisfied. The recovery rates were in the range of 98.21% to 102.18%, with RSDs between 0.35% and 0.96%. The test samples showed good stability under room temperature, freeze condition and three cycles of freeze-thaw condition. The RSDs of peak area of 6 samples placed at room temperature for 3, 6, 12, 24, 48, 96 hours were between 0.35% and 1.02%. The RSDs of 3 samples placed in refrigerator at -20℃ for 5, 10, 15 days were between 0.58% and 1.67%. The RSDs of 3 samples which were frozen and thawed three times were between 0.26% and 0.93%. The method was proved to be good when applied to case samples. For example, once we received an unknown sample seized by police, and then used the extraction and chromatography Methods to analyze the sample, the major analyte’s retention time was consistent with safrole standard and the quantitative result was 7.08%. This method was rapid, simple, effective and suited for quantitative determination of safrole.
  • Application of GPC in the Examination of Plastic Evidence
    GUO Hongling, QUAN Yangke, LI Haiyan, SHI Huixia
    Forensic Science And Technology. 2015, 40(3): 208-210. https://doi.org/10.16467/j.1008-3650.2015.03.009
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    Polymers are frequently encountered in trace evidence laboratories in crime scene investigation, various types of plastic products can be collected. Fourier Transform Infrared Spectroscopy (FTIR) is usually used to determine the type of polymers and Scanning Electron Microscope/Energy Dispersive X-ray Spectrometry (SEM/EDX) is used to determine the elements of additives in polymer samples. Molecular weight and molecular weight distribution are important parameters to characterize polymers, but they have not been used in forensic science before. For some plastic samples, there is no or few additives present in them, which makes the differentiation between them more difficult. In many cases, the polymer type and the additives information are not enough to differentiate plastic samples. Molecular weight and molecular weight distribution will be a big help to differentiate polymer samples of the same type. Gel Permeation Chromatography (GPC) with low angle laser light scattering detector is very useful in determining molecular weight and molecular weight distribution of polymers even without the relative standards. In this paper, four automobile headlight screens and three preservative film samples were analyzed by GPC method to determine the molecular weight and molecular weight distribution. Weight average(Mw),number average(Mn) and molecular weight distribution or polydispersity index (PDI) of samples were measured. Normal temperature GPC method was applied for examining the automobile headlight screens and high temperature GPC method was used for examining preservative film samples. Student’s t test was used to compare the mean value of Mw, Mn and PDI of pairs of samples. The Results show that all the plastic samples can be differentiated by the combination of these three parameters. GPC method provides a new way to further examine the plastic samples which could not be differentiated by FTIR and SEM/EDX.
  • Enhancement of the Cyanoacrylate Fumed Fingermarks Using Ardrox
    FENG Yaxian, LUO Yaping, HUANG Hao
    Forensic Science And Technology. 2015, 40(3): 211-214. https://doi.org/10.16467/j.1008-3650.2015.03.010
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    Objective To determine the dyeing effect of Ardrox fluorescent liquid on non-porous surfaces after development of fingerprints by cyanoacrylate glue. Methods Study was carried out to establish the method to enhance the fingermarks fumed by cyanoacrylate glue using Ardrox fluorescent liquid. Comparative experiments were performed on 12 kinds of common plastic, glass or other non-porous objects with rhodanmine 6G, BBD and gentian violet solution, respectively. All experiments were ensured to be coupled with the most optimized conditions and fuming time. Fingermark aging period test of 1, 3, 5, 7 and 15 days with cyanoacrylate-Ardrox approach was demonstrated as well. Results On plastic, glass and other non-porous substrates, the cyanoacrylate glue-Ardrox fluorescent liquid method had shown the developed images, obviously superior to those with rhodanmine 6G, BBD and gentian violet, with the most significant effects on tinfoil, black plastic bags and zip-top cans. On the surfaces with light or dark colors, Ardrox usually be able to demonstrate the significant effects of fingermarks except those on disks, of which the background irradiated by UV light weakened the contrast of reflection. Ardrox fluorescent liquid should be used as quickly as possible, and the best performance appeared within 24 hours after made up. The pictures needed to be taken immediately right after dyeing. According to the data, samples left over for 15 days or less could be clearly developed, while the effects of dyeing reduced significantly after 15 days. Conclusions The developing method with cyanoacrylate glue and Ardrox fluorescent liquid features reliability, distinct imaging and high fluorescence.
  • Comparison of Spectral Imaging and Traditional Optical Methods for Enhancing Blood Fingerprints on Glossy Paper
    ZHAO Lihua, HE Haiming
    Forensic Science And Technology. 2015, 40(3): 215-217. https://doi.org/10.16467/j.1008-3650.2015.03 .011
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    Objective To compare the effects of spectral imaging and traditional optical Methods for blood fingerprints on glossy paper with complex background and the regularity and characteristics of eliminating background, for the purpose of selection the most optimal photographical method. Methods Three Methods were employed to take photo of blood fingerprint samples on 21 different kinds of glossy paper separately: the optical directional reflection at small angle with light illumination for photography; the visible spectrum imaging at 420~720 nm band of the Multiple Spectral Imager, classifying images and filtering the mixed; the full-wave band CCD system for the constant temperature locking by reducing temperature and filtering noise, illuminating with light in the dark field, and the reflex photography by 254 nm short-wave ultraviolet band. Results Different images of blood fingerprints on 21 kinds of glossy paper had been taken, among which, the image effects were obviously improved by light illumination method at 19%, Multiple Spectral Imager at 33% and full-wave band CCD system at 66% respectively after eliminating blood fingerprint background interference. Conclusions Different imaging Methods by multiple spectra for blood fingerprints on different glossy paper could eliminate the interference under some specific background, and to improve the imaging effects. It is suggested to select the right photographic method by the corresponding spectrum according to the real effect of eliminating interference from the background of the blood fingerprints.
  • Analysis of Human Static and Dynamic Characteristics in Video
    BAI Shengxue, LIU Tao, WANG Xin, YANG Ming
    Forensic Science And Technology. 2015, 40(3): 218-221. https://doi.org/10.16467/j.1008-3650.2015.03.012
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    Video investigation focuses on the videos involved in criminal cases and the relevant clues could be obtained through analyzing the persons and objects in videos. A video is composed of multi frame images, and characterized by intuitiveness and dynamic continuity. As the video provides both the static and dynamic human feature, some important characteristics can be extracted from the video, which are favorable for criminal investigation. In this paper, it is expounded that the main content of video image analysis and inspection of a human is to extract and analyze the static and dynamic characteristics. With video of high quality, the static characteristics such as the appearance and posture become the key points of video image analysis and inspection. In reality, the surveillance video is often apt to be influenced by various factors, such as lamplight, bad weather, distance, image distortion. The videos recorded by the monitoring system often tend to be blurring and it is difficult to extract the suspect’s facial features from those poor quality videos. Therefore, it is unlikely to get enough information if only relying on the static characteristics. However, movement and gait of the suspect could be totally recorded by surveillance video, which are less susceptible to the external environment. It is advantageous to combine human static and dynamic characteristics in videos to obtain more valuable information. An actual case determination indicates that both the static and dynamic characteristics could be closely interrelated, hence provides new clues for the criminal investigation and new Methods for portrait comparison, suspect identification as well as case linkage. At the same time, this paper proposes a standard inspection procedure of human characteristics in surveillance video, which promotes the standardization and routinization of video inspection and greatly enhance the efficiency of the analysis and inspection.
  • Discrimination of Laser Printing Documents by SEM/EDX
    WANG Xiaobin, HUANG Jiantong
    Forensic Science And Technology. 2015, 40(3): 222-226. https://doi.org/10.16467/j.1008-3650.2015.03.013
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    Objective This paper aims to distinguish documents printed with different brands and models of laser printer using scanning electron microscopy with energy dispersive X-ray (SEM/EDX). Methods Documents printed with 10 brands and models of laser printers were collected, and SEM/EDX was used to analyze the inorganic elements of characters on the documents. Each sample was tested three times and energy spectra and mapping analysis charts were obtained. Qualitative and semi-quantitative analyses were also conducted and the elemental components and their distribution in ink of printing characters were determined. In order to analyze the influence of paper, 10 brands of A4 xerographic papers were collected and elements were analyzed on the blank area. Results 10 brands and models of laser printers were divided into 4 categories according to element C, O, Na, Al, Si, Cl, Ca, and Fe detected from the printing characters. The ratio of C/O and Ca/C of laser printing characters were calculated to distinguish the brands and models of laser printer in the same category. The analysis of A4 xerographic paper indicated that the paper type had greater impact on the Results of quantitative analysis of ink than qualitative analysis result. Conclusions SEM/EDX is a very attractive technique for laser printer ink analysis, and can be used to discriminate laser printing documents. It can also be used in the examination of secondary laser printing documents. This approach is simple, rapid, reliable and non-destructive.
  • Development of Personnel Information Acquisition System
    QI Fengliang, ZOU Jixin, YU Jian, QIN Da
    Forensic Science And Technology. 2015, 40(3): 227-231. https://doi.org/10.16467/j.1008-3650.2015.03.014
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    Personnel Information Acquisition System(PIAS) is introduced with the requirements of the public security information construction project, which integrates software and hardware efficiently. It is designed for police officers to collect a suspect’s personal information which will be shared with different police databases in real time, such as basic information, fingerprints, palm-lines, photos, DNA, footprints, communication information, and the like. The personnel information is stored and compared with the varied databases and the matching Results will inform the relevant local police in time automatically. With the help of PIAS, the information collection rate and utilization efficiency are improved dramatically and will be of great help to the crime investigation. In this paper, we present a design and implementation of PIAS, which consists of the multi-functional software and the well-designed information acquisition hardware. The hardware includes a personal computer as the control terminal, different information acquisition equipment, which are integrated on a worktable designed up to the standard of ergonomics. Such details are explained as on software architecture, database design, network topology, system interface with the sequence diagram and functionalities of the system. The information collected by the equipment is then processed and transferred in the format compatible with different databases. The personal data is stored and compared in different databases, and the hit Results will be transmitted automatically to the terminal in local police station. For example, a fugitive will be identified immediately if his fingerprint matches with the one at the crime scene database and the feedback will be to sent the local police shortly after the criminal’s fingerprints are recovered. In order to implement this function well, the information acquisition system has access to other databases. If this system is used in a certain province, it has to implement interfaces specified for the local databases or integrative application platform of the police in that province different from others. The system also provides the basic functions for management such as user and authority management, message management, information acquisition equipment management, system log, statistical analysis, etc. It is believed that with PIAS, information sharing between above all public security information systems will be much easier, practical and accurate.
    • Reviews
  • Forensic Application of Human Characters Inferred from DNA
    SUN Qifan, ZHAO Lei, JIANG Li, QUAN Yangke, ZHAO Xingchun, LI Caixia
    Forensic Science And Technology. 2015, 40(3): 232-235. https://doi.org/10.16467/j.1008-3650.2015.03.015
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    DNA, the basis of biological heredity and breeding, having different composition and configuration of sequence bases to define the code of life, controls the diversity of people’s height, color of skin and complexion, hair texture, bones, nerves and the others together with the growth, development and senescence of organs. DNA keeps records of all genetic information of an individual. Because of its uniqueness (DNA sequence is different from each other between every individual with the exception of identical twins), identity (DNA sequence of an individual is same among his/her various organs with the exclusion of the transplanted or the mutated tumor tissues) and inheritance (each individual’s nuclear DNA in all somatic cells comes from parents and the mitochondrion from the maternal), DNA plays the decisive role in individual identification and consanguinity verification. Today, forensic DNA test mainly relies on STR (short tandem repeats) multiplex amplification. But STR primarily localizes in the non-coding region of a genome, thus difficult to provide more information about the phenotypic characteristics of people. Therefore, the current DNA tests are mostly used for “comparison and match”, demonstrating unavailability for cases without target suspects and/or any other clues although the biologic samples collected from the scene have plenty of biological information waiting for exposure and exploitation. Recently, the depiction of human characters inferred from DNA is becoming an important research hotspot in forensic community. Such information as the one of anthropology, physiology, pathology and/or phenotype can be deduced from the donor’s DNA that the feature of an individual’s appearance, disease attributes, ethnic and geographical affiliation would be portrayed. At present, some related technology and Methods have gradually begun to be employed in criminal casework．In this paper,we summarize the general situation of the research depicting human characters inferred from DNA and extrapolate its developmental trend.
  • Progress of Latent Fingerprint Visualization
    FANG Yao, SHA Wanzhong
    Forensic Science And Technology. 2015, 40(3): 236-239. https://doi.org/10.16467/j.1008-3650.2015.03.016
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    Over the last 100 years, the Methods for traditional visualization of latent fingerprints have been improved, and meanwhile, many new techniques and approaches have been applied in this area. In general, the latest technology mainly includes new material, electrochemiluminescence imaging, biotechnology, spectral imaging, mass spectrometry, etc. The novel visualization technology overcomes the limitation of the traditional ones in many aspects of visualization sensitivity and efficiency, especially wins a lot of applauses when dealing with the old latent fingerprints at trace level, marking the beginning of a new era of latent fingerprint visualization. However, the new technology over-relies on some expensive equipment and reagents, and requires high demanding practices. As a result, a great deal of work has to be done further, to make sure that it can completely replace the traditional Methods in more practical term in the foreseeable future. This paper reviews the research progress in the application of new technology, and looks forward to the future development of latent fingerprint visualization technology.
    • Technical Notes
  • Death from Delayed Traumatic Intracerebral Hematoma Three Days after Trauma
    YANG Ming, ZHANG Wei, WANG Dan, WU Song, 2LI Jianquan
    Forensic Science And Technology. 2015, 40(3): 240-241. https://doi.org/10.16467/j.1008-3650.2015.03.017
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    Usually the delayed traumatic intracerebral hematoma (DTICH) occurs within 24 hours post injury. An extraordinarily rare case is presented here in which a 47-year-old man who died from an intracerebral hemorrhage that occurred three days after he suffered from head injury with his occipital part bumping onto a wall during a dispute. Though getting increased headache after injury, no evidence of abnormality of head was identified by computerized tomography (CT) scan the next day. Nevertheless, just three days after the trauma, the man abruptly went into coma when driving and died soon. A large intracranial hematoma was found with pathological anatomy, which was confirmed under microscope to be caused from fresh bleeding. The incidence of vascular malformation and/or hypertension was ruled out through autopsy. The delayed traumatic intracerebral hematoma was determined to be the cause of death.
  • Effect of Sample Collection and Preservation on DNA Yield
    DENG Shujiao, LI Ping, HUANG Guiqing, YANG Dian
    Forensic Science And Technology. 2015, 40(3): 242-243. https://doi.org/10.16467/j.1008-3650.2015.03.018
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    Objective To explore the effect of sample collection and preservation on DNA yield. Methods The fresh anti-freezing blood from 30 volunteers was respectively dropped onto a swab from the casing for collection and preservation of biological sample, and the ones of both the cuspidal and the common medical. Each of the blood specimens was separately preserved in the casing or paper bags for a week. Every piece of DNA from the blood specimens was extracted by magnetic beads method in combination of automation workstation and was quantified by ABI 7500 Real Time System. Results The average DNA concentration was (2.54±0.63) ng/μL for the blood specimens collected and preserved with the casings, (2.06±0.44) ng/μL and (0.93±0.59) ng/μL for those blood specimens which were collected with cuspidal swabs and common medical ones and followed to preserve in paper bags. The DNA yield was obviously higher using the casings than that of either the cuspidal swabs or the common medical ones to collect and then preserve in paper bags. Conclusions This test suggests that it is better to choose the casings for collection and preservation of biological sample than the cuspidal and the common medical swab.
  • Genetic Polymorphism of 18 STR Loci of Han Population in Shijiazhuang
    ZHOU Jing, NIU Yiping, DU Xiao
    Forensic Science And Technology. 2015, 40(3): 244-245. https://doi.org/10.16467/j.1008-3650.2015.03.019
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    Objective To investigate genetic polymorphism of 18 STR loci on human chromosomes of Han population in Shijiazhuang. Methods Allelic frequencies for 18 STR loci and genetic parameters for forensic purpose were calculated. Results No deviations of allelic frequency from Hardy-Weinberg equilibrium expectations were observed (P>0.05). 198 alleles and 695 genotypes were gained. Allele frequencies varied between 0.002 and 0.545; heterozygosity (H) between 0.624 and 0.932; matching probability (Pm) between 0.016 and 0.189; power of discrimination (DP) between 0.811 and 0.984; polymorphism information content (PIC) between 0.580 and 0.910; power exclusion (PE) between 0.321 and 0.861. 12 off-ladder alleles of 8 STR loci were found. Conclusions 18 STR loci of Han population in Shijiazhuang are with relatively high polymorphism, and suitable for forensic individual identification, paternity testing, and relative research.
  • Determination of Emulsion Explosive Residues
    FAN Jundan, WANG Lichun
    Forensic Science And Technology. 2015, 40(3): 246-248. https://doi.org/10.16467/j.1008-3650.2015.03.020
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    Objective To explore the reasons why the contents of ammonium ion and nitrate ion in the explosion residue of emulsion explosive were lower than that of normal explosives. Methods The emulsion explosive residue samples were collected from a crime scene and an explosion experiment scene, respectively. The samples were analyzed by ion chromatography and the contents of ammonium ion and nitrate ion were quantitatively determined. Results The contents of ammonium ion and nitrate ion in blank samples, case samples and experimental samples were in the same level. Conclusions According to the emulsion explosive formula, the content of ammonium nitrate in emulsion explosive normally is in the range of 78%~82% (typical content is 74.3%). However, as advanced production technology and effective emulsifier have been employed in production process, the mixture of ammonium nitrate and composite oil in emulsion explosive is more homogeneous, and then the oxidation-reduction reactions of emulsion explosives in explosion become more thoroughly. This Results in the quite lower contents of ammonium ion and nitrate ion in the explosion residue of emulsion explosive, which is consistent with the Results of the case and the verification experiment described in this article.
  • Identification of Common Scene Fingerprint’s Papillary Lines
    WANG Jingdu, WANG Xuqing
    Forensic Science And Technology. 2015, 40(3): 249-251. https://doi.org/10.16467/j.1008-3650.2015.03.021
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    Fingerprint’s papillary lines, varying from person to person and immutable, are the basis for individual and forensic identification. The examination and comparison between fingerprints depend on identifying the papillary lines of fingerprints recovered from scenes. In the process, the perpetrators can be recognized directly, or analyzed on their personal specifics, with their familiarity with the scenes and the course of committing crimes deduced, thereby offering an abundance of clues and evidence for relevant case investigations. However, the fingerprints left on scene may be papillary line prints, or likely furrow line prints, or the mixed of the lines above because of the influence of factors including scene environment, attached mediums, contacted objects, criminal psychology, course of committing crimes, various forces exerted by fingers involved, and the fingerprint recovery techniques. Therefore, cautions must be taken so that the identification quality can be ensured. In this paper, several sorts of fingerprints usually found on scene are used to probe into correctly identifying papillary lines of fingerprints so as to make the fingerprints verification gone through rightly.
  • A Method for Reconstructing Vehicle-pedestrian Accident Scene Based on Pc-Crash Simulation
    ZHANG Yonggang
    Forensic Science And Technology. 2015, 40(3): 252-255. https://doi.org/10.16467/j.1008-3650.2015.03.022
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    To further test the effectiveness of the method used to reconstruct a vehicle-pedestrian accident scene based on Pc-Crash simulation, a real vehicle-pedestrian accident case recorded by freeway surveillance video was introduced and the crash speed was estimated. The speed of the vehicle was calculated by PC-Crash simulation and video image processing technique respectively. The Results show that the speed of the vehicle simulated by PC-Crash was consistent with the speed calculated by the video image processing technique. The reliability and feasibility of the vehicle-pedestrian collision reconstruction was further verified. A reliable result could also be obtained by Pc-Crash simulation when the trace information was inadequate. This paper demonstrates that the accident scene reconstruction based on the Pc-Crash simulation is instructive for accident investigation.
  • Quantitative Analysis of Acetone in An Unusual Death
    SONG Lijuan, ZHAO Peiduo, ZHANG Guanghua
    Forensic Science And Technology. 2015, 40(3): 256-258. https://doi.org/10.16467/j.1008-3650.2015.03.023
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    Objective To solve an unusual death case and develop a method for determining concentration of acetone in blood or urine samples from the dead body by headspace gas chromatography (HS-GC), which is quite helpful under certain circumstance when autopsy can’t be performed because of social customs, religious belief or other reasons. Methods A 67-year-old man, who had diabetes, was found dead in a hotel room and his family didn’t agree to perform an autopsy. In order to determine the cause of death, the blood and urine samples were sent to laboratory for poison and drugs analysis, but no common poison was found. Based on the excellent volatility, acetone in blood or urine samples was analyzed by a head-space gas chromatography system with hydrogen fire ionization detector (HS-GC/FID). Qualitative analysis result was obtained according to retention time, and quantitative analysis was performed by internal standard (tert-butyl alcohol) method. The average peak area derived from three replicate injections of each sample was used for the calculation of acetone concentration in blood or urine. Results Concentration of acetone in blood and urine was 6.89 mg/100mL and 57.1 mg/100mL respectively, both were much higher than the normal value. Conclusions Determination of acetone in blood or urine by HS-GC/FID provides a useful evidence for determining the manner of death, which is especially effective when short of pathology data. In such casework, thorough information about the dead should be taken into consideration to ensure the scientific deduction.

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