The effectiveness of identifying the author of an illegal document by using text mining was investigated. The suspected writing evaluated in this study was a claim of responsibility written by a 14-year-old boy, which stated that he committed the “Kobe child murders” in 1997. It was compared with control writings including confessions, and an essay that we knew were written by the same boy, as well as with irrelevant materials including various essays written by five junior high school students, and claims of responsibility in four past criminal cases. First, the writings in each document were digitalized and converted to text files. Then, the relative frequencies of bigram of letters, bigram of part-of-speech taggers, sentence lengths of each document, and rate of using Kanji, Hiragana, and Katakana were calculated. Results of sammon multi-dimensional scaling and hierarchical cluster analysis indicated that the text in the suspected writing was arranged identically or similarly to groups of texts in control materials, where they were arranged differently from groups of texts in irrelevant materials. In a separate analysis, the suspected writing was substituted with a document written by a different offender and we conducted the identical procedure described above. Results demonstrated that texts in the suspected writing were in a different form control and irrelevant texts. These results indicated the effectiveness of identifying an author by using text mining when examining forensic documents.

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  Because of its high usefullness and discrimination power, short tandem repeat (STR) analysis has been playing the most important role in forensic DNA examinations for more than 10 years. Recently, Promega has developed a PowerPlex Fusion system which genotypes 22 autosomal STR, Amelogenin and DYS391 loci. In this study, we validated the Fusion system for forensic purposes using the 3500 xL with a threshold value of 175 RFU and the 3130 xl with 150 RFU.
  The PCR cycle was adjusted to 28 cycles to give an optimal peak height from 1 ng DNA. The reproducibility of the electrophoresis for the 3500 xL was improved by changing the run voltage from 15 kV to 13 kV. When 13 anomalous samples that tended to be designated as off ladder (OL) at D12S391 locus were injected at least 10 times, the 3500 xL with 15 kV gave the highest observation of OL, followed by the 3500 xL with 13 kV and the 3130 xl with 15 kV. Most of the spectral pull-up ratios were within 2.68% for the 3500 xL, and within 5.85% for the 3130 xl. The spectral pull-up from red (CXR-ET) to yellow (TMR-ET) was more obviously generated by the 3130 xl than by the 3500 xL. We also examined sensitivity, mixed DNA, base line noise in electrophoresis, peak height ratios, stutter ratios, 20% cut-off filter, aged bloodstains, animal DNAs, and tolerance to PCR inhibitors. We concluded that the Fusion system could be used as a STR kit for forensic purposes. However, cautions should be taken, since 1) the inter locus and the intra color peak balances were slightly worse than those of the Identifier plus kit, 2) the loci of high molecular weight tended not to be detected in degraded samples, and 3) the OL designation was occasionally observed at the D12S391 locus especially when using the 3500 xL.

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  In forensic investigations, ABO genotyping is often performed to obtain information for individual identification. This information is especially effective in the analysis of highly decomposed samples with which the serological method for ABO typing cannot be used due to ABH antigen deterioration. The authors previously reported on the development and improvement of a microarray-based method that can be applied for simultaneous ABO genotyping and human identification using two pairs of probes to detect major O or B allele-specific single nucleotide polymorphisms (SNPs) in the ABO gene and a probe to determine the human-specific D17Z1 sequence. In this study, a probe pair for B allele-specific SNPs was redesigned and selected because those used in the previous study appeared less than optimal in regard to specificity between BB and B heterozygous genotypes, which could give rise to false results. When DNA from bodily fluids (blood, saliva, semen and vaginal fluid), tissues and blood from cadavers, and blood stains were analyzed using the redesigned chip, the O and B index values, which reflect fluorescent patterns of each probe pair, could be clearly separated according to genotype. On the basis of these results, threshold values for each index were set and their use for genotype determination in analysis of aged stains and bone samples was verified. Finally, validation was performed with respect to the effect of the amount of input DNA for ABO genotyping by analyzing 0.0625 to 0.5 ng of DNA with the BO genotype. The results demonstrated that more than 0.25 ng of DNA is necessary for accurate genotyping with this method. Due to its simplicity, rapidity and accuracy, the approach is expected to be useful for ABO genotyping in forensic investigations.

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  The purpose of this research is to measure coefficient of friction of the road surface in the winter season that varies on temperature, snow compression, snow coverage and other factors. In the winter, road conditions change over time, the fresh snow on the road surface changes to compacted snow, slush, melts and becomes water by the rising temperatures and the passage of the vehicle. It is possible to obtain an accurate velocity by using coefficient of friction according to the road conditions.
  Therefore, this research measured coefficient of friction of the road surface conditions of fresh snow, compacted snow, and slush as can be predicted on the winter road surface. For example, with usual slush that can be seen when there is little snow and heavy traffic, the coefficient of friction of the state of slush is 0.35-0.40, the state of melting slush is 0.40, the state of almost melted and water is 0.54. It is necessary to use the appropriate coefficient of friction depending on the road conditions for the same slush.
  In addition, this research measured the coefficient of friction from a vehicle that side slipped and stopped on a slope in compacted snow. From the results of measurement, the coefficient of friction from a side slipped vehicle stopping on a slope in winter road surface with compacted snow was not observed as much as the coefficient of friction of side slipped and braking experiments. The numerical value of the coefficient of friction when a vehicle is stopped at a traffic light could be considered for future reference.

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  The concealed information test (CIT) estimates whether an examinee knows crime-relevant information on the basis of differences in physiological responses between the crime-relevant and irrelevant information. To examine the differences in physiological responses, this study used the following four statistical values: Lykken's scores, likelihood ratios, effect sizes, and p values of randomization tests. A total of 152 participants, 80 of whom actually knew information related to a mock theft, received a CIT about the theft. From these CIT data, the four statistical values were calculated. On the basis of these values, whether each participant knew the theft-related information was ascertained. High correct discrimination ratios were seen for effect sizes (92.4%) and p values of randomization tests (90.6%) compared to Lykken's scores (83.2%) and likelihood ratios (74.8%). Areas under the receiver operating characteristic curves were also greater for effect sizes (0.919) and p values of randomization tests (0.928) than for the other statistical values. These results suggest that effect sizes and p values of randomization tests are promising for examining the physiological differences in the CIT.

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  Accurate DNA quantification is required for the short tandem repeat typing of forensic samples. Various commercial DNA quantification kits for forensic DNA analysis have recently been released. However, DNA quantification may fail if too much PCR inhibitor is extracted with the target DNA sample. Therefore, this study experimentally evaluated the degree of the alteration of DNA quantification results of various commercial DNA quantification kits (Takara RR281, Quantifiler Duo DNA Quantification Kit, Plexor HY System, Investigator Quantiplex HYres Kit, Quantifiler Trio DNA Quantification Kit, and Quant-iT dsDNA HS Assay Kit) in the presence of various concentrations of PCR inhibitors such as hematin, humic acid, indigo carmine, melanin, and tannic acid. Compared to the other kits, the DNA quantification abilities of the Investigator Quantiplex HYres Kit and Quant-iT dsDNA HS Assay Kit were not negatively affected by high concentrations of hematin. The DNA quantification abilities of the Quantifiler Trio DNA Quantification Kit and Quant-iT dsDNA HS Assay Kit were not negatively affected by high concentrations of PCR inhibitors containing humic acid, indigo carmine, or melanin. The DNA quantification abilities of the Investigator Quantiplex HYres Kit and Quantifiler Trio DNA Quantification Kit were not negatively affected by high concentrations of tannic acid. Furthermore, the DNA quantification ability of the Quantifiler Trio DNA Quantification Kit was more reproducible than those of the other kits. Moreover, this kit was able to assess the degree of DNA degradation by comparing quantified both the short amplicon (80 bp) and long amplicon (130 bp). However, the short amplicon was not negatively affected by high concentrations of PCR inhibitors in contrast to the long amplicon. These results indicate forensic DNA analysts should select the appropriate DNA quantification kits that are unaffected by PCR inhibitors and carefully interpret DNA quantification results.

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  Abuses of new psychoactive substances have recently become serious social problems. When synthetic cannabinoids are consumed, most of the drugs are not detected in unchanged form from the urine. In that cases, it is difficult to determine what drug was consumed in drug testing. If blood and saliva of suspects are obtained immediately after drug consumption, unchanged drugs could be detected from the specimens. Therefore, on-site sampling of these specimens are effective to determine the consumed drugs. We examined how police officers easily obtain blood and saliva of suspects on site and what drug concentrations are needed to detect drugs in blood and saliva obtained by the sampling methods. First, blood and saliva sampling methods were examined using various collecting tools. For blood sampling method, it was effective to bleed from a fingertip with a lancet and then to absorb the blood to paper pulp. Blood of approximately 5 μL was obtained by this safe and simple method. For saliva sampling method, dropping saliva directly into a 25 mL centrifuge tube (direct sampling method) was convenient for drug analysts. However, because some subjects felt it unpleasant that the sampling situation was watched by the observer, the alternative sampling method, absorbing saliva in a mouth with a cotton swab was also used. Saliva of at least 50 μL was obtained by the two methods. Next, five drugs (JWH 018, 5F-APINACA, 4-MeO α-PVP, 4-Cl AMP and MeBP) in blood and saliva were analyzed using a liquid chromatograph-ion trap mass spectrometer to estimate the concentrations required for drug detection. The limits of detection of five drugs were in the range of 0.1-10 ng/mL for blood (5 μL) and 0.01-1 ng/mL for saliva (50 μL) obtained by the direct sampling method. On the other hand, absorbing saliva by a swab made drug detection difficult because synthetic cannabinoids, JWH 018 and 5F-APINACA, were strongly adsorbed in the swab. It is considered that saliva obtained by the direct sampling method is effective for drug testing because the sampling is rapid and simple, a large volume of saliva is obtained, and the drug concentrations in abusers' saliva are generally high as compared with those in blood.

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  FDS (Fire Dynamics Simulator) is the open-source software developed by NIST of USA. Pyrolysis is considerd to solve the one-dimensional heat conductivity equation in three directions respectively. FDS is applied widely for building fires, tunnel fires and so on. Since combustion analysis is significant for proactive measures, we have acquired enough skill to use for science programs. We have executed fire spread simulations of small plastic gears with a diameter of 30 mm and 10 mm in thickness in a closed duct to evaluate the capability of FDS as a development tool. In this report, we have investigated the combustion characteristics of an upper gear for the distance between two gears and aperture ratio of upper surface of the duct. We prepared an analytical model with 2.5 mm mesh size to compare time variation of temperature with the experimental results. Our numerical calculations correlated well with our experimental results. In addition, the time variation of concentration of a fuel gas showed a physically reasonable behavior. For the small distance between gears, the fuel gas generated from an under gear mainly plays an important role in ignition of the upper gear. We understand the effect of temperature and fuel concentration generaterd by the under gear. FDS Ver. 6 is applicable to solid combustion phenomena for 10 mm size plastics.

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