25 February 2015, Volume 40 Issue 1
    

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  • LIU Shi-quan,LUO Ya-ping,WU Jian
    Forensic Science And Technology. 2015, 40(1): 1-7. https://doi.org/10.16467/j.1008-3650.2015.01.001
    Abstract ( ) Download PDF HTML   Knowledge map Save
    The interpretation of fingerprint evidence depends on the judgments of fingerprint examiners. Basing on fingerprint identification methods, standards and working experience, fingerprint examiner conducts fingerprint analysis, comparison and finally gives expert opinion which is one of the legal forms of evidence.This study assessed the accuracy of different judgments made by fingerprint examiners following the analysis process. 106 agencies were invited to take 4-trail experiment for identification following analysis, comparison and evaluation process. We compared the examiner’s judgments against ground truth and used a net-work based fingerprint identification analysis platform to evaluate how fingerprint examiners document their analysis during the identification process. The experiment information of each agency was recorded during the fingerprint identification process and data was calculated by statistical software R for statistical analysis .The results showed that different examiners demonstrated different accuracy of judgments and different mechanisms to reach them. The results also showed that there is a strong relationship between minutiae selection reliability and minutiae quantity and fingerprint quality.
  • WANG Wan-ting,ZHAO Ya-bin,LUO Ya-ping
    Forensic Science And Technology. 2015, 40(1): 8-11. https://doi.org/10.16467/j.1008-3650.2015.01.002
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    Objective To explore a new approach for developing latent fingerprints by using fluorescent titanium dioxide nano-particles. Methods Titanium dioxide nano-particle was coated with fluorochrome and the morphological feature was observed by scanning electron microscope (SEM). Five kinds of non-porous surfaces, including glass, transparent plastic, colored plastic, tile, and can were used in this experiment. Fingermarks were deposited after wiping fingers over the forehead in succession and then pressing them onto substrates. The fluorescent powder was applied to fingermarks deposited on the surfaces. The fingermarks were stored for 1, 4, 7 and 15d or heated at 100℃ for 1~72h before treated. The samples were then observed in the luminescence mode using a Polilight alternative light source with the emission set at excitation wavelength of 515nm. Results Observation of the prepared powders using SEM shows that the dye-coated particles’ size varies from 100 to 200nm in diameter. The fluorescent dye/TiO2 powder was light pink particles under white light. Illuminated at 515nm, TiO2 particles coated with fluorescent dye exhibited strong fluorescence. When latent fingerprints detected with this fluorescent powder, particles could be selectively adhered to the latent fingerprint deposit. Fingerprints developed with fluorescent dye/TiO2 showed strong orange-red luminescence and clear details of ridge. On several nonporous substrates, the new powder gave a lower background and thus better contrast in developed fingerprints. Colored surfaces were also tested and the results demonstrated the advantages of the fluorescent powder with better contrast. Storage time of fingerprints did not make significant difference in the quality of developed fingerprints on glass. The fluorescent dye/TiO2 powder gave satisfactory results when applied to 15-day fingerprints retained on substrates of glass, transparent plastic and cans. The enhancement for detail was slightly less than that with fresh prints, but the powder still revealed clear images. While for colored plastic, the image of older marks (>7d) developed by fluorescent dye/TiO2 powder showed less ridge details. Fingerprints on tile developed by fluorescent dye/TiO2 powder showed strong fluorescence, but the image of older marks became indistinct over time. When the fingerprints heated for 1~72h were developed with the fluorescent dye/TiO2 powder, the quality of developed fingerprints was as for fresh fingerprints. However, a slight reduction in fluorescence intensity was observed towards the 72h setting as fingerprint deposit dried out and lost its stickiness. Conclusions Fluorescent nano-dye/TiO2 powder is a new developing method that can be applied to develop fresh as well as aged latent fingerprints on nonporous substrates without background color requirements. This method is very sensitive and selective; the fluorescence can be excited at 515nm and observed through an orange-red long-pass filtering barrier. This fluorescent powder is easy to use, low-cost and non-toxic, it can be used for developing latent fingerprints.
  • WANG Yue,HU Shu-liang,LIU Jin
    Forensic Science And Technology. 2015, 40(1): 12-14. https://doi.org/10.16467/j.1008-3650.2015.01.003
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    Objective Since tetramethylbenzidine has substituted benzidine to visualize latent blood fingerprints, it is the preferential choice for developing latent blood fingerprints based on the principle that its oxidized resultant can make the fingerprints of shallow-color or colorless turn into cyan color. But, the fingerprints developed by this method show low contrast when the observed objects are red and even lower the fuscous, are difficult or cannot be photographed. This paper tries to explore a new technique to enhance the development of blood fingerprints on red surface. Methods The solution of 0.25% light green SF yellowish was sprayed onto latent blood fingerprints deposited on red surfaces. The revealed fingerprints were taken pictures, some parts of the fingerprints were further amplified to find out the enhancement effect. Results The light green SF yellowish was very sensitive to develop the blood fingerprints deposited on red surfaces, capable of making 100% visible the samples of latent blood fingerprints prepared in the laboratory. The developed fingerprints showed clear and coherent ridge, distinct contrast without background color and when amplified, the chosen parts of them appearing the features of detail. Conclusions 0.25% light green SF yellowish can effectively visualize latent blood fingerprints on red surface with very distinct contrast.
  • LI Kang,TU Ni,LI Xiao-jun,HAO Xiang,GUAN Chen
    Forensic Science And Technology. 2015, 40(1): 15-18. https://doi.org/10.16467/j.1008-3650.2015.01.004
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    Objective This study aims to select the appropriate exciting light source and filter to visualize latent fingerprints on non-porous surface fumed with the novel fluorescent cyanoacrylate powder. Methods The appropriate light source and filter were selected by means of the fluorescence spectrometer along with both the excitation and emission spectrums decided. Results The analysis of new fluorescent cyanoacrylate powder by fluorescence spectroscopy showed that the excitation wavelength of light source was 235~580nm with the maximum peak at 530nm where the fluorescent intensity was the biggest, and also quite strong absorbance peaks were obtained at 450nm and 360nm, with 45nm Stokes shift. Verification experiments indicated that the effect of developing fingerprints was good in the range of 235~580nm. Conclusions The fingerprints fumed with the new fluorescent cyanoacrylate powder can be visualized under the light of UV, violet, blue, yellow, and green with the merits of large Stokes shift and high fluorescent intensity, easy to eliminate the interference of background fluorescence, and facilitative to select filters. The fingerprints can be visualized clearly with the fluorescence selected by comprehensive consideration of the above factors. Besides the property of fluorescent powder, the effect of developing fingerprint with fluorescence relies on the exciting light source, the filter, and the inherent luminescence characteristics of submitted exhibits and the conditions of exhibit surface.
  • WANG Ming-chao
    Forensic Science And Technology. 2015, 40(1): 19-23. https://doi.org/10.16467/j.1008-3650.2015.01.005
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    Objective Genipin, an extract from gardenia fruit, can react with amino acid in the fingerprint deposits, making it a fingerprint developing agent. Latent fingerprints on paper developed with genipin shown blue under white light but red fluorescence under an alternative light source. This method is safe and environment-friendly by use of this natural product. Nowadays, there are a variety of methods chosen to develop latent fingerprints on porous surface, for example, those of using ninhydrin, DFO, IND, PD and ORO. Presently, forensic scientists pay more attention to the combination of these methods. Therefore, how to find the good association of these methods to enhance the number and effect of developed fingerprints appears to be a trend in fingerprint technology research. This paper investigated the sensitivity of genipin agent and explores the correlation of using genipin, ninhydrin and DFO, and finally sets up a sequential procedure which can apparently elevate the effect of developed prints on paper surface. Methods Natural fingerprints ranging from strong to weak (‘depletion’ prints), taken from ten donors, were deposited on strips of copy paper, newspaper, kraft and offset paper. We used “split print” approach by evenly cutting the fingerprint into two parts. Firstly, in order to evaluate whether the soak time could influence the result, we immersed the same sample in genipin solution for one, two and three times respectively and observed the effect under white light and alternative light source respectively. Secondly, as DFO should be used before ninhydrin, we designed four procedures by using genipin prior to ninhydrin and comparing with single use of genipin, ninhydrin prior to genipin and comparing with single use of ninhydrin, genipin prior to DFO and comparing with single use of DFO, and finally DFO prior to genipin and comparing with single use of genipin. Each experiment was conducted separately, and the result was observed both under white light and fluorescence. Results It failed to enhance the fingerprint developing effect when samples were treated with different times of single use of genipin either under white light or fluorescence, but the addition of DFO prior to genipin or genipin prior to ninhydrin presented better effect than single use of one agent although none of better results were obtained with using genipin prior to DFO or ninhydrin prior to genipin. Conclusions The method of sequential addition of DFO next genipin and final ninhydrin is more efficient with enhancing the effect of the developed fingerprints while genipin is sensitive enough to develop fingerprints with sample-treating only once.
  • ZHANG Ting,YANG Rui-qin
    Forensic Science And Technology. 2015, 40(1): 24-27. https://doi.org/10.16467/j.1008-3650.2015.01.006
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    Pores abounds in finger skin’s ridge, through which sweat is excreted and deposited on the surface of the skin. Sometimes, sweat contains special substances including drug and its metabolites. These substances in fingerprints can reflect a possibility of an individual’s ingesting drugs. In recent years, the importance of analyzing some excreted and deposited compounds in fingerprints has drawn more attention because these compounds may provide more significant information of an individual and his/her past behavior. Determination of fingerprints’ residues is helpful for criminal investigation and evidence identification. Many techniques such as FT-IR spectroscopy, infrared spectral imaging, Raman spectroscopy, Raman spectral imaging mass spectrometry, gas chromatography-mass spectrometry, high performance liquid chromatography, liquid chromatography-mass spectrometry, and immunological approach, have been widely used. Among these, the immunological approach can not only make latent fingerprints visualized but also deliver more accurate and sensitive biochemical information from fingerprints. In this article, the recent progress and application of immunological method for developing fingerprints are presented by focusing the determination on amino acid, ingested drug in fingerprints and aged latent fingerprints as well.
  • Research Articles
  • LIU Xiao,LIN Cheng-xi,ZHANG Ping-ping,YANG Xiao-man,ZHAO Yong,LI Chun-feng,SUN Chong-yun,QIU Jing-fu,YANG Rui-fu,ZHOU Lei
    Forensic Science And Technology. 2015, 40(1): 28-34. https://doi.org/10.16467/j.1008-3650.2015.01.007
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    Objective To develop and evaluate an up-converting phosphor technology based on lateral flow assay (UPT-LF) for qualitative and quantitative detection of morphine (MOP) and methamphetamine (MET) in urine. Methods With up-converting phosphor nano-particles (UCP-NPs) as the biological tracer, two competitive mode-based LF strips, MOP-UPT-LF and MET-UPT-LF were developed for quantitative detection of MOP and MET in urine. The comprehensive performances of MOP-UPT-LF and MET-UPT-LF were evaluated systematically. In order to explore the detection limit of UPT-LF for trace analysis, MOP-UPT-LF strips were used to test standard samples with series of concentrations, and then the detection limit and ability of quantitative detection were determined. According to the standard of detection threshold for MOP and MET, the quantitative detection performances (including detection sensitivity and linear range) of MOP-UPT-LF and MET-UPT-LF were optimized and re-evaluated. For the evaluation of qualitative detection ability, the results of MOP-UPT-LF and MET-UPT-LF for on-site urine samples were compared with those of colloidal gold based LF (CG-LF), and LC-MS and GC-MS were used as the gold standard for the detection of MOP and MET, respectively. For the evaluation of quantitative detection ability, the results of MOP-UPT-LF and MET-UPT-LF for simulated positive urine samples were compared with those of LC-MS and GC-MS, respectively. Results For trace analysis, the detection limit of MOP-UPT-LF could reach 1ng/mL with a linear range from 1ng/mL to 5000ng/mL (r = -0.98172,P < 0.0005). For routine detection with the threshold of standard, the detection limit of MOP-UPT-LF was 50ng/mL with a linear range from 50ng/mL to 3000ng/mL (r = -0.98464,P < 0.0005). The detection limit of MET-UPT-LF was 100ng/mL with a linear range from 100ng/mL to 5000ng/mL (r = -0.99964, P < 0.0005). According to the detection of urine samples, the performance of qualitative and quantitative detection of MOP-UPT-LF and MET-UPT-LF could meet the need of the on-site rapid detection of MOP and MET in urine. The qualitative detection results of MOP-UPT-LF and MET-UPT-LF for on-site urine samples were consistent with those of colloidal gold and no false-positive and false-negative results observed. The ROC area of MOP-UPT-LF and MET-UPT-LF reached 1.000±0.000 (95%CI). For quantitative detection of simulated positive urine samples, the recovery rate was 77%~133% with the mean of 109% and CV of 21% for MOP-UPT-LF, for MET-UPT-LF the recovery rate was 80%~131% along with the mean of 112% and CV of 17%. After statistical analysis, there was no significant difference (P>0.05) between MOP-UPT-LF/MET-UPT-LF and LC-MS/GC-MS for quantitative detection of MOP and MET in urine. Conclusions With the novel optical nano-particle (UCP-NPs), the traditional LF assay was integrated with biosensor based on automated analysis and two kinds of UPT-LF strip were developed to meet the need of on-site qualitative and quantitative detection of MOP and MET. With GC-LF as the reference for qualitative detection and LC-MS/GC-MS for quantitative detection, the comprehensive performances (including detection limit, qualitative accuracy, and quantitative ability) were evaluated systematically. The good qualitative and quantitative detection performance of MOP-UPT-LF and MET-UPT-LF offers a new choice for on-site drug screening.
  • MA Meng-yun,WANG Jiang-feng
    Forensic Science And Technology. 2015, 40(1): 35-39. https://doi.org/10.16467/j.1008-3650.2015.01.008
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    Objective In order to investigate the regular pattern about temperature change during postmortem decomposition under certain conditions and to offer scientific proof to the estimation of postmortem interval, meanwhile, to make clear the actual temperature rising caused with the maggot growing in carcass and provide a reference for the criminal investigation. Methods The pig carcasses were left in field in different seasons, the sensors of thermometers were put under the tongues and inserted into the rectums about 5cm to monitor temperature changing. The maggots developing in the carcasses were observed and measured day by day. At a constant temperature in lab, a piece of pig liver infested with maggot at different density was used to reveal the temperature changing with infested maggot. The obtained experimental data was analyzed statistically. Results Carcass temperature elevated along with dense aggregation of larvae, rising about 8℃ in spring while in summer even up to 22℃. The bigger the maggot density was, the higher and quicker the temperature rose in the infested area. Conclusions The temperature of carcass can be elevated with maggot infestation and reversely affect the relative insect developing. The temperature rising in carcass should not be neglected especially when maggot is observed.
  • ZHANG Da-lei,ZHANG Ji-lin,CAI Zhi-cheng,CHEN Qi,LIAO Lin-chuan
    Forensic Science And Technology. 2015, 40(1): 40-44. https://doi.org/10.16467/j.1008-3650.2015.01.009
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    Objective To establish a GC/MS derivatization method for determining the 4-bromo-2, 5-dimethoxy-phenethylamine in blood. Methods Blood sample was extracted and purified by Bond Elut Centify® solid phase extraction column after diluted to four times by deionized water. The residuum was derivatized by trifluoroacetic anhydride. 4-bromo-2, 5-dimethoxyphenethylamine and 4-phenylbutylamine (internal standard) were analyzed by gas chromatography-mass spectrum. The ions m/z 242 and m/z 91 were applied in quantitative analysis for 4-bromo-2, 5-dimethoxyphenethylamine and 4-phenylbutylamine, respectively. Results The limit of detection was 6 ng/mL in blood sample and the calibration curve was linear in the range of 0.02~10μg/mL (=0.9993) for 4-bromo-2, 5-dimethoxyphenethylamine. The RSDs of intra-day and inter-day were less than 10%; the average extraction recovery of 4-bromo-2, 5-dimethoxyphenethylamine was about 69%.Conclusions This method is rapid, sensitive and suitable for qualitative analysis of 4-bromo-2, 5-dimethoxyphenethylamine in blood.
  • XU Fang-min,LI Hai-bo,LIU Ling-yun
    Forensic Science And Technology. 2015, 40(1): 45-48. https://doi.org/10.16467/j.1008-3650.2015.01.010
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    Objective Endosulfan has been often used to poison fish pond water in Jiangyin city. As the concentration of endosulfan in poisoned water is very low, it is revry difficult to detect endosulfan from water. In this paper, a new simple and rapid method for analysis of endosulfan in poisonedfish pond water was presented. Methods The dispersive liquid-liquid micro-extraction technique (DLLME) coupled with gas chromatography-ion trap mass spectrometric detection (GC-MS) was used to analyze endosulfan in samples of poisoned fish pond water. The disperser, containing extraction solvent, was rapidly injected into the sample solution with a syringe, making a cloudy solution formed. Because of the extraction solvent rapid diffusing into the sample solution and getting in touch with the analyte in the cloudy solution, the analyte was quickly transferred into the extraction solvent so that the extraction equilibrium could be achieved in a short time. After centrifuging, the fine particles of extraction solvent were precipitated in the bottom of the conical test tube and then were determined by GC-MS. Results Under the optimum conditions,the extraction rate of endosulfan in poisoned fish pond water was more than 90%, the limits of detection and the limits of quantitation were 0.005µg/mL and of 0.017µg/mL,respectively. The linear relation was quite good between 0.02µg/mL~0.20µg/mL. Conclusions The advantage of this new method is simple to operate, rapid, low cost, high recovery and accuracy. This method is suitable for casework.
  • CHEN Quan-jin,HUANG Jun-can,CHEN Hang
    Forensic Science And Technology. 2015, 40(1): 49-54. https://doi.org/10.16467/j.1008-3650.2015.01.011
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    Objective To study the influence of white noise on the extraction of phonetic feature and to offer a reference for identification of the speech mixed with noises. Methods After embedding the different intensity of white noise into the speech samples which were selected from the DARPA TIMIT acoustic-phonetic continuous speech corpus, we utilized speech workstation to extract pitches and formants from both pure speech and noisy speech of different signal-to-noise ratio(SNR) thereby analyzing the influence of white noise on the parameters of phonetic feature. Results Formant frequency kept relatively stable in low noisy condition but appeared shifting or even undetected under certain conditions with the noise strength enhancing. For each order of formant, the anti-noise ability was different, with the low order showing strong and highly stable but the high order weak and poorly stable. However, the pitch retained steady in various noisy conditions.Conclusions Reducing SNR can result in formant frequency shifting or vanishing. The influence of noise on the formant of high order is bigger than that of the low order. Pitch keeps highly stable in noisy environment.
  • XU Guo-tian
    Forensic Science And Technology. 2015, 40(1): 55-58. https://doi.org/10.16467/j.1008-3650.2015.01.012
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    Objective In practice, such situations are often encountered that the files have not been restored because of the incorrect recovery tools and/or varied restoring methods. In this paper, three data recovery modes used with NTFS storage device were analyzed and their effects were tested and compared. Methods For the same NTFS storage device, we used NTFS log inspection software developed from previous research to test the recovery choice based on NTFS log file, utilized the quick scan function of Final Data to test the recovery choice based on MFT, and used the full scan function of Final Data to test the recovery choice based on characteristic value. Finally we compared the effect of the three choices and analyzed their recovery principles. Results The recovery choices based on NTFS log file and MFT could obtain comprehensive information but were not suitable for files deleted long before. Though the recovery choice based on characteristic value played poor effect on restoring either the non-contiguous files or the file names and file-creating time, it could restore the files deleted long before albeit time consuming. Conclusions Three methods can be applied in casework with their integrative utilization.
  • BAO Qing,WANG Shi-quan,SHEN Si
    Forensic Science And Technology. 2015, 40(1): 59-62. https://doi.org/10.16467/j.1008-3650.2015.01.013
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    Objective Currently the aging file suspected to be made intentionally, albeit difficult to determine, has positive significance in document inspection because a file can be identified as fake once the artificial aging is confirmed when the real written time is different from that of the claimed. Methods We used the writing made with ball-pen blue oil as the research object. Because the tri-aromatic methane dye in ball-pen blue oil will accelerate its aging when exposed to ultraviolet, an aging equation, if founded, can reveal the aging rate of tri-aromatic methane with time elapsing based on some appropriate assumptions. Since almost all the ultraviolet lamps are linear structure and within some distance, for example, a file irradiated intentionally, emit their energy uniformly and transmit the ultraviolet rays spherically, the aging equation can be used to calculate the energy of any point on paper with help of proper coordinates. According to the aging degree of tri-aromatic methane dye at different position on paper surface, we could verify whether a file was natural aging or artificial with ultraviolet lamp. Results For one point of the file artificially aged with ultraviolet lamp, the content of initial methyl violet, a constituent of tri-aromatic methane dye, was divided by that of post-aging, thus getting a quotient which was converted into a value of natural logarithm; when the value of natural logarithm was further again divided by the value of energy irradiated from ultraviolet lamp on that point, the obtained quotient was a constant (named as K) with small floating range and the degree of linear regression greater than 99%. This could probably prove that our deduction was reasonable and met actuality both for the equation on aging and the function on energy density distribution. However, this law does not exist for natural aging file. Conclusions The artificial aging file with ultraviolet lamp can be quantitatively measured by the function and law we discovered in this study.
  • Reviews
  • WANG Jian,YANG Chao-peng,HE Guang-long,ZHONG Jing-fang
    Forensic Science And Technology. 2015, 40(1): 63-66. https://doi.org/10.16467/j.1008-3650.2015.01.014
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    Computed tomography (CT), an imaging device using computer two-dimensional reconstruction, can obtain images of body’s cross-section based on the different X-ray absorption rate of human tissues. CT’s density resolution is significantly better than that of the X-ray’s, making it able to conduct the volume and multiplanar reconstructions(VR), maximum intensity projection(MPR), shaded surface displays (SSD) and other process. CT has an important value in diagnosis of tumors, vascular malformations and other diseases, fractures, joint ectopia, organ rupture, bleeding injury, gunshot, fragments exploded out, inhalant substances and other foreign materials in the body. CT has been applied in forensic pathology. In this article, we reviewed some papers published in recent years in forensic science journals domestic and abroad to show the present CT applications in forensic pathology, hoping to provide new ideas for forensic pathological research and casework.
  • WANG Fu-lei,WANG Gang,YANG Chao-peng,TIAN Xue-mei
    Forensic Science And Technology. 2015, 40(1): 67-70. https://doi.org/10.16467/j.1008-3650.2015.01.015
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    Domestic and foreign researches have shown that the morphological character of sternum has strong connections with sex. The sternum length, gladiolus size, manubrium cubic shape and sternum dimension were often used as indicators of sex, but it is still disputable to identify sex with the index of sternum. Therefore, to establish an equation of differentiating sex is considerable based upon selecting the high credible elements indicated above so as to define a threshold value for identifying sex and achieve higher accuracy. Present data, home and abroad, demonstrates that the accuracy of sex identification with the morphology of sternum is greater than 90 percent. The manual measurement of the sternum length is the main method to acquire relative values, which is time-consuming and laborious, easily affected by operators. New medical imaging technology, for example, the multi-layer spiral computed tomography, is bringing new resort to identify sex through sternum, convenient to handle and operate. More accurate and accessible data will be acquired by 3D reconstruction imaging combined with multiplanar reconstruction, X-ray photographing and CT scanning. This paper summarizes the relevant reference on sternum morphology of different sex, and especially focuses on the forensic data of assistance in the individual identification, hoping to shed light on the study of 3D reconstruction imaging of sternum morphology and improve the innovation of method for individual identification by sternum.
  • Technical Notes
  • YANG Xue-ying,CAO Hai-dian,PEI Li,XU Peng
    Forensic Science And Technology. 2015, 40(1): 71-73. https://doi.org/10.16467/j.1008-3650.2015.01.016
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    Objective The genetic analysis of ITS2 region presented here is to detect the species of plants from spice drugs using DNA barcoding method. Methods DNA from samples of “spike 99”, “K2” and “7#” collected from cases were extracted using QIAGEN DNeasy plant mini kit. The ITS2 sequence forward primer was 5’-GCGATACTTGGTGTGAAT-3’, and the reverse was 5’-GACGCTTCTCCAGACTACAAT-3’. PCR amplification was performed in a 25µL reaction mixture. Purified PCR products were sequenced in both directions with the primers used for PCR amplification on 3730XL Genetic Analyzer. To estimate the quality of the generated sequence, the original forward and reverse sequences were assembled using CodonCode Aligner V 3.71 and the conserved 5.8S and 26S rRNA sequences were removed from the ITS2 sequence. The PCR amplification products using ITS2 primers were sequenced, analyzed and BLAST in NCBI database. Results The samples of “spike 99”, “K2” and “7#” contained organic compounds which had been determined by GC-MS. “spike 99” was found to possess JWH-073 and JWH-018 components, and JWH-018 in “K2”, cannabis in “7#”, respectively. As for the DNA analysis, one sequence from both “spike 99” and “7#” and two sequences from “K2” were 100% homologous with the ITS2 sequences of Medicago sativa, cannabis sativa, humulus lupulus and Abelmoschus manihot. Conclusions All samples containing constituents from at least four kinds of plants: Medicago sativa, cannabis sativa, humulus lupulus and Abelmoschus manihot. The results were consistent with their chemical constituents and gave the evidence that the DNA approach was an essential alternative to identify the species of plant for the drug abused. DNA barcoding, involving the amplification and sequencing of relatively short, standardized genetic loci, provides a powerful tool to identify the species of plant.
  • LIN Yan,LI Wei-hua
    Forensic Science And Technology. 2015, 40(1): 74-76. https://doi.org/10.16467/j.1008-3650.2015.01.017
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    The evidence exploration by means of polygraph (lie detector), named map test method, is often implemented with the map of the surveyed area in foreign countries. In a case, taking place three years before, where the outlaws killed a person and burned the body into the cremains which were packaged and thrown away, we used the three-dimensional street image instead of the traditional floor plan, and achieved remarkable results. In order to find the likely place where the cremains of the victim were cast, we utilized the three-dimensional street image to arouse the murderers’ memory that involved with their action and location to throw the murdered cremains. Corresponding to the place that the cremains were discarded, the murderers showed distinct response in the polygraph. With the clue we discovered, the cremains were found and the case was solved. The three-dimensional street image will offer greater assistance in the polygraph test with its more vivid, more stimulating power and the ability to plunge the subjects into the real scene.
  • ZHANG Guang-lang,YAN Jun-hong,XU Lian-sheng
    Forensic Science And Technology. 2015, 40(1): 77-78. https://doi.org/10.16467/j.1008-3650.2015.01.018
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    we were asked to determine six packs of samples which were suspicious of crystal methamphetamine or “ice”. All samples were shown white crystals under microscope, similar to “ice” and could not be analyzed by GC/MS, so we conducted elemental analysis using scanning electron microscope/energy dispersive spectrometry first and then determined the chemical components using X-ray diffraction. Five packs were potassium aluminum sulfate and one pack was sucrose.
  • TIAN Rui
    Forensic Science And Technology. 2015, 40(1): 79-81. https://doi.org/10.16467/j.1008-3650.2015.01.019
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    The pistol of type 64 has been fading out of people’s sight. Yet its modified versions are still found in civil society. Because of the modifications with various means and techniques as well as the dissimilar parts, there are differences from the normal counterparts at both the patterns and positions of marks left by the shot bullet-heads and cartridge, bringing difficulties to investigators. However, these marks can play their effect in identifying the relative guns involved in cases. Here, we describe such a case. Through marking a shell hook with color and testing the shell with homemade primer which was fired by the examined non-systematical type 64 pistol, we confirmed that the examined shell was indeed shot by the examined non-systematical type 64 pistol, providing an example to identify the fired gun with the abnormal mark left on shell hook.
  • CUI He-qun,ZHAO Qiang
    Forensic Science And Technology. 2015, 40(1): 82-83. https://doi.org/10.16467/j.1008-3650.2015.01.020
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    This paper introduces digital forensic examination on Android smart phone using MTP protocol to build up a virtual file system in PC. By the request of MTP protocol, PC can operate and then view and copy files on some Android smart phones. The data from the phone involved in the case could not be extracted with current smart phone forensic tools, because it set up a mobile phone anti-theft lock and USB debugging was not open. The author queried the production date of smart phone and concluded the Android System version was supported by MTP protocol, which was used to find password in Tencent folder and exact SMS\IM records from the phone. Therefore, this paper provides a new method for unlocking smart phone whose screen lock is set by third party software.
  • ZHANG Jian,LI Hong-wei,WANG Le,FENG Yu,YAO Yi-ren,YANG Fan,LU Xin,KONG Zhi-ming,BAI Xue,ZHAO Xing-chun
    Forensic Science And Technology. 2015, 40(1): 84-86. https://doi.org/10.16467/j.1008-3650.2015.01.021
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    Objective To investigate the polymorphism of 18 short tandem repeats (STR) loci of Qiannan Han population. Methods Using domestic DNATyperTM19 fluorescent labeling kit, and combining with PCR amplification and automated fluorescent detection of capillary electrophoresis, we carried out the DNA typing of 18 STR loci of 1, 104 unrelated individuals of Han population from Qiannan in Guizhou, China, and conducted statistical analysis to calculate the distribution of allelic frequency and other population genetics data. Results Genotypes of the 18 STR loci were in line with Hardy-Weinberg equilibrium (P > 0.05). Statistical analysis showed that the population genetics parameters of the 18 STR loci were as follows: heterozygosity (H) ranging from 0.622 to 0.915, matching probability (Pm) 0.017 to 0.220, power of discrimination (DP) 0.780 to 0.983, polymorphism information content (PIC) 0.540 to 0.900, and power of exclusion (PE) 0.318 to 0.826. In the 18 STR loci, the polymorphism indicators of PentaE were the highest, but those of the three of D3S1358, TH01 and TPOX the lowest. Conclusions This investigation demonstrates that allelic frequency of these 18 STR loci is well-distributed and high of polymorphism in Qiannan Han population.