In a criminal investigation, it is important to clarify the origin of the extracted DNA from available biological samples. In recent years, a new approach for the identification of body fluid stains has been demonstrated and involves a comparison of specific mRNA expression levels. Here, we used real-time RT-PCR to examine the expression levels of STATH, HTN3, MUC4, and ESR1 genes from salivary, nasal, and vaginal secretions which are often thought to be difficult to discriminate between. STATH was expressed at high levels in all salivary (dCt=1.27±3.18, n=10) and all nasal secretions (dCt=−0.99±3.94, n=8), and at low levels in 3 of the 10 vaginal secretions (dCt=16.34−17.47). HTN3 was expressed at high levels in all salivary secretions (dCt=0.67±3.08). MUC4 was expressed at relatively high levels in all vaginal secretions (dCt=4.97±2.36, n=10), and at moderate levels in 5 of the 10 salivary secretions (dCt=8.55−10.40) and in 4 of the 8 nasal secretions (dCt=6.56−8.23). ESR1 was expressed at relatively high levels in all vaginal secretions (dCt=5.79±2.90), but no expression was found in salivary and nasal samples. These results indicate the possibility for specific discrimination between various body fluids. To test the practicality of this, gene sensitivity and stability were examined in saliva, semen, and blood stains. Several genes, including ACTB, STATH, HTN3, PRM2, SEMG1, and HBB, were shown to be detectable even in small volume (0.1 μL) stains and were also expressed in 1-year-old stains. mRNA stability was dependent on favorable environmental factors, such as dryness and shading. In addition, the successful detection of target genes from mixed stains and simulated casework samples might promise the utility of this assay. The mRNA assay therefore appears to be a novel tool for body fluid identification from biological samples.

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  Previous research on speaker identification has demonstrated the effectiveness of using syllables containing a nasal consonant. In this study, we investigated the contributions of nasal consonants (/m/ and /n/) and vowels (/i/, /e/, /a/, /o/, and /Ɯ/) to identification accuracy by using them separately in speaker identification experiments. Japanese monosyllables with nasal onsets were recorded from 50 male speakers using a condenser microphone. Two recording sessions were held and thus non-contemporaneous speech data were obtained. Nasal consonants and the following vowels were excerpted from the recorded monosyllables, and 30th-order cepstral coefficients were calculated for each as acoustic features. The results revealed that the accuracy of identification using nasal consonants was not as high as that using vowels; more than six nasal tokens for a given speaker needed to be registered in order to match the score afforded by one vowel token for the same speaker. The higher vowels, /Ɯ/, /e/ and /i/, yielded significantly better identification rates than the lower vowels, /a/ and /o/, and the alveolar nasal /n/ was better than the bilabial /m/. We also conducted a factor analysis in order to clarify the effects of the attributes of speakers and speech samples on the differentiation between speakers with similar speech characteristics. Analysis was performed on frequently confused speaker pairs using 11 parameters for vowels and six parameters for nasals. The parameters were selected from various attributes related to the physiological properties of the speakers and the acoustic properties of their speech. The results showed that irregularity in phonation and the degree of vowel nasalisation were among the most influential factors. The physical size of the speakers and the average fundamental frequencies also affected the accuracy of speaker identification.

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  In order to estimate type and trajectory of the fired bullet from the analysis of the ricochet mark, we carried out the gunfire test against the inclined target. 1.2 mm thin steel plates were used as intermediate targets in this study. The following are types of cartridges which were used: 25 AUTO., 32 AUTO., 7.62 mm Tokarev, 380 AUTO., 38 SPL. (FMC), 38 SPL. (LRN), 9 mm Luger and 45 AUTO.. The target was put in a wooden frame. The angle of incidence was changed by rotating the wooden frame.
  We could classify the deformation morphology on the thin steel plate into 4 patterns: Ricochet mark without the crack (Type 1), Ricochet mark with the small crack (Type 2), Ricochet mark with the large crack (Type 3), Penetration (Type 4). Metal from the bullet surface was left on the surface of the target. It was thought that the crack in the edge of the ricochet mark (Type 2 or 3) was caused by the friction arising from the rifling rotation of the fired bullet. The length of the ricochet mark in the longitudinal direction L increases with increase of the kinetic energy of the bullet E. The value of L was relative to the kinetic energy resolved into the horizontal component of the velocity Ecos²θ_i (θ_i: the angle of incidence). Except for 380 AUTO. and 38 SPL., the value of L was almost independent of E and Ecos²θ_i respectively. The ratio of the angle of ricochet θ_r to the angle of incidence θ_i was around 1 to 2. Therefore, caliber and type of a fired bullet and the trajectory can be determined from the analysis of the ricochet mark and the contour when the bullet is fired into a 1.2 mm thin steel plate.

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  Currently, polygraph examinations in Japan use the concealed information test (CIT) to determine whether a suspect knows specific details of a crime. The present study examined the accuracy of the CIT as a memory detection technique in a mock-theft experiment. Participants were randomly assigned to either an encoding or non-encoding group. An expert polygrapher who was not informed of the group assignments, conducted a CIT that consisted of two questions. One inquired about a card number chosen by the participant, and the other regarded an item that had been stolen. Analyses focused on the second question. Roughly 20% of cases were judged inconclusive while sensitivity and specificity for the remaining cases were 86% and 95%, respectively. Analysis was repeated using modified Lykken scoring, and rates of inconclusive cases, sensitivity, and specificity by this method were 25%, 83%, and 91%, respectively.

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  To obtain DNA typing results from forensic biological samples is occasionally difficult, since they are complex and diverse. AmpFℓSTR^® Identifiler^® Plus PCR Amplification Kit (IDPlus) was developed to improve the success rate of DNA typing from such samples by Applied Biosystems. Forensic biologists must be cautious in DNA typing when considering the characteristics of the Kit used for analyzing in such samples. Therefore, to reveal to the characteristics of IDPlus Kit is very important to increase the reliability and probative value of DNA typing in the trial and investigation. In this study, IDPlus is evaluated for the characteristics and the DNA detectability. We also compared IDPlus with AmpFℓSTR^® Identifiler^® PCR Amplification Kit (ID) by analyzing samples difficult to obtain DNA types. The results from the PCR inhibitor study using bloodstain on soil or denim indicated that IDPlus was more resistant to PCR inhibitors than ID. In the study of analyzing degraded DNA, there were no significant differences to be found except for the sensitivity. The peak corresponding to insufficiently amplified products due to a point mutation on primer binding site was higher using IDPlus than ID in electropherogram. Also the anomalous peaks which were observed in analyzing same mammal animal DNA samples were higher. Hence, IDPlus is considered to be very effective leverage to samples analysis which is difficult to detect allele due to PCR inhibitors. The primer binding ability to the template DNA was altered when using IDPlus compared with the ID so this should be taken into consideration. Forensic biologists must be aware the possibility of the discordance of DNA typing results between IDPlus and ID. From the results of this study, IDPlus was considered to be utilized to analyze forensic samples difficult to detect allele using ID.

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  Poly(ethylene terephthalate) is a dominant synthetic fiber for garment and it occupies 85% of synthetic fiber products, and is the most encountered single fiber during the trace physical evidence identification. For the single fiber identification, chemical analyses play a significant role. In this experiment, we focused on the physical properties, such as, their orientation and inorganic additives. We applied the discrimination of poly(ethylene terephthalate) by observation of the intensities profile of polarized light and scattering light near the melting points with the polarized microscope and accurately temperature controlled hot plate. Poly(ethylene terehthalate) was put cross Nicole position. Most of the samples showed the similar profile of poly(ethylene terephthalate) to the poly(ethylene terephthalate) mixed with cotton. The intensity profile was stronger than that of intensity before melting, but several samples did not show these phenomena. In regard with the orientation, light profiles were different in low, medium and high oriented poly(ethylene terephthalate) fibers. As an addition of inorganic compound, Kaolin made the melting point higher than other samples. In many cases, TiO₂ was added as preparing dull fibers, in this experiment, sufficient reproducibility was not obtained in these samples, but morphological observation could discriminate at 0.05% of adding of TiO₂ to fiber. The fibers with this amount of TiO₂ added could not be distinguished by chemical analysis by widely used infrared spectroscopy. In the recycled poly(ethylene terephthalate) fiber, the polarizing light intensity was weak. These results indicate not only chemical analysis but also measuring the physical property and morphological observation are also effective for the forensic discrimination of fibers.

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  The authors have reported 4 successfully-detected cases of helium in postmortem blood by headspace-gas chromatography (HS-GC). Postmortem blood was collected into a depressurized 4-ml glass vial to prevent volatilization loss of helium. MICROPACKED-ST column (2.0 m×1.0 mm i.d., 80/100 mesh) was used as a separation column, and thermal conductivity detector was selected as a gas chromatographic detector. Argon was used as a carrier gas, and the flow rate was set at 8.3 ml/min. After 0.5 ml air was released into the vial, 0.5 ml headspace gas was manually injected to the instrument. In this analytical condition, helium was well-separated from other gases in the atmosphere. This HS-GC method was applied to real blood samples of 4 suspected cases of helium inhalation, resulting in successful detection of helium in blood in all cases.
  In the case of a suicide by helium inhalation, it is generally difficult to determine the cause of death from an autopsy finding. This case report provides a practical method to obtain direct proof of helium inhalation.

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  Isolation of high-quality nucleic acids of microorganism is essential for the molecular testing of biological warfare agents (BAs). In this study, we evaluated three commercially available nucleic acid extraction kits, IT1-2-3^TM (IT), Bio Bulwark^TM pretreatment reagent kit (BB) and MORA EXTRACT (ME), using spores of Bacillus subtilis as a model of Bacillus anthracis. The extraction efficiencies of genomic DNA using IT and BB were approximately 10% and 30%, respectively. The ratio of absorbance (260 nm/280 nm) of each extracted sample showed from 1.7 to 2.0, and indicated that the purity of extracted DNA using these kits was sufficient for the molecular testing. BB could inactivate more than 5×10⁷ spores at the beads beating process. While surviving spores were detected after the beads beating process of IT, and the residual spores might be captured in a spin column filter. Although these kits are enabled for the extraction of nucleic acids of BAs with easy handling, the efficiency of extraction and efficacy of inactivation of BAs are different. So it is important to understand the characteristics of each kit before use.

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  The identification of body fluids at crime scenes provides critical evidence that can be used to prove the occurrence of a crime. In this study, the genome profiling (GP) method was utilized to identify saliva and sweat. We randomly amplified cDNA obtained through the RT-PCR approach using RNA samples extracted from saliva and sweat with four different random primers, and performed temperature gradient gel electrophoresis between 15-65°C. The Sp-2 primer was the only primer which generated the species identification dots (spiddos) in all body fluids. The numbers of spiddos found were 11.6±0.89 in saliva and 3.0±1.73 in sweat, and the body fluid type specific spiddos were obtained from electrophoresed gel. Along with previously reported data of semen and vaginal fluid, it was indicated that the GP method might distinguish those four kinds of body fluids. This novel assay is a simple and economical method. Therefore it may be an effective tool for the identification of body fluids at crime scenes. However, further detailed studies, including sensitivity, reproducibility, environmental effect and the effectiveness of detection from mixed stains are necessary before actual forensic investigations.

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正誤表
本誌第17巻第2号P.59の図に誤りがありました．
下記の通り訂正します．
誤　Fig. 11縦軸最下部　10²
正　Fig. 11縦軸最下部　10^－2

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