In this paper, validity of the identification of rubber/photopolymer stamps produced from the same character design inspection was done. Stamps produced from the same character design have the same stamp face and their impressed images are expected to be too similar to be identified. Ten rubber stamps and 10 photopolymer stamps were used for the examination. The template matching between the standard image and other stamped images was performed with the rubber stamp images and photopolymer stamp images. Intra-individual variance and inter-individual variance of stamped images were calculated and compared. The average of the matching rate of intra-individual variance was compared with the average of the matching rate of inter-individual variance. The results showed no significant difference between these averages. The inseparability of the intra-individual variance and the inter-individual variance suggested the difficulty in the stamp identification.

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  In general, the attachment of human hair sheath is considered as one of the most important factors in detecting STR genotypes from single hair samples. Thus, it is difficult to genotype STRs from naturally shed human hair samples using AmpFℓSTR Identifiler PCR Amplification Kit. In this study, we examined the conditions involved in determining STR genotypes from a single hair root of naturally shed human hair focusing on two kinds of commercially available DNA extraction kits; a QIAamp DNA Micro kit (Micro kit) and an ISOHAIR kit (ISOHAIR kit), and the relationship between the concentration of extracted DNA and the numbers of STR loci genotyped.
  As a result, based on the protocol of DNA quantification adopted in the police labs in Japan, the DNA amounts were sufficient to quantify in approximately 28% or 36% of 72 naturally shed human hair samples using a Micro or an ISOHAIR kit, respectively. There was no significant difference in genotyping STRs between the two extraction methods. If a quantitative value was estimated based on a Ct (cycle threshold)-value, the extracted DNA was duplicated to amplify by 28 PCR cycles. Alternatively, if a quantitative value showed “ND (not detected)”, the extracted DNA was performed by duplicate PCR amplification for 32 cycles.
  Consequently, in the case of a 28 cycle-amplification, when a quantitative value was more than 0.04 ng/μl, the genotyping result was obtained accurately at almost all loci by both extraction methods. On the other hand, in the case of a 32 cycle-amplification, there was a tendency that more accurate genotypes are obtained by a smaller size of an amplicon except a few loci. It indicated that the accurate genotyping rate should not depend only on the size of PCR products.
  Therefore, when a DNA sample shows “ND” as an estimated value, more careful interpretation should be necessary to genotype by increasing PCR cycles to 32, or more strict making decision not to proceed to any PCR amplification should be performed.

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  We examined whether powders and transfer sheets for detecting latent fingerprints affect DNA extraction and subsequent short tandem repeat (STR) typing adversely. To examine the powders, saliva and blood samples were smeared and dried on glass slides, and then adhered with aluminum powder, black powder, magnetic powder (NBS), magnetic powder (Sirche), SP black and indigo. To examine transfer sheets, saliva and blood samples were smeared and dried on gelatin sheets, JP sheet and Lifter. DNA was extracted from the powder-adhered samples or the samples on the sheets, quantified by a real-time PCR assay, and the STR typing was performed using the Identifiler kit.
  The aluminum powder and the SP black affected the storage of the DNA solution, and required a centrifugation step to remove the powders, or required TE⁻⁴ buffer for DNA elution instead of water. The magnetic powder (NBS) made the DNA extraction impossible, when an excessive amount of the powder was adhered. However, the DNA extraction was possible, when most of the powder was removed with a magnetic brush. The black powder, the magnetic powder (Sirche) and the indigo gave enough DNA concentration and full STR profiles. All the transfer sheets did not give adverse effects.
  As simulated casework samples, 20 fingerprints deposited on a glass slide in two different ways were enhanced with the aluminum powder and transferred to the gelatin sheets. DNA was extracted from the gelatin sheets, and the residual portion on the glass slide. The DNA concentration ≥0.01 ng/μl was obtained from 2 samples for the residual portion of 20 fingerprints deposited 2 hours after washing hands, and 7 samples for that of 20 samples deposited after touching forehead, cheeks and neck. The STR typing was performed from the samples ≥0.01 ng/μl. Full STR profiles were obtained from 6 samples (≥0.024 ng/μl) and partial STR profiles from 3 samples (0.10-0.12 ng/μl) when the residual portion used.

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  Ninhydrin and its analogues are wildly used to detect latent fingerprints on porous materials. When the contrast of ninhydrin-developed fingerprints is not sufficient, indium chloride (InCl₃) treatment has been used to improve their images. For non-porous materials, polycyanoacrylate p-dimethylaminobenzaldehyde (DMAB) method and tris thienyl europium chelate (T.TEC) method have recently been developed in Japan. In this study, we examined the effects of these latent fingerprint detection methods on short tandem repeat (STR) typing. Saliva and blood samples were attached to and dried on copy paper for the experiments of the ninhydrin, 1,2-indanedione, and 1,8-diazafluoren-9-one (DFO). Saliva and blood samples were also smeared and dried on glass slides for the experiments of the polycyanoacrylate DMAB, and the T.TEC. DNA was extracted from the samples, quantified by a real-time PCR assay, and the STR typing was performed using the Identifiler kit.
  Various ninhydrin solutions including the acetone and acetic acid solution tended not to reduce the DNA concentrations, and provided full STR profiles. Heating by putting an iron directly on the samples remarkably reduced the DNA concentrations for 30 seconds. It was recommended that direct-heating be prohibited and that the steam from an iron be used in the ninhydrin method. The InCl₃, the indanedione, the DFO, the polycyanoacrylate DMAB and the T.TEC methods did not reduce or slightly reduced the DNA concentrations, but full STR profiles were obtained. The transfer membranes used in the InCl₃ method gave low DNA concentrations because the samples were likely to remain in the residual portions on glass slides. The ultraviolet light (350 nm) used in the polycyanoacrylate DMAB and the T.TEC methods did not adversely affect the DNA concentration and the STR typing.

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  There is still a considerable number of seizures of illicit cannabis in Japan. In addition, the prevalence of herbs containing synthetic cannabinoids becomes a serious social problem. Because of an increasing number of cannabis and herb samples encountered in forensic science laboratories, it is required to develop a rapid method for identification and discrimination of cannabis and its related herbal products. In this study, general methods for microscopic morphological examination were improved. The decolorization of cannabis in 10% NaOH in water-methanol mixture (1:1, v/v) at 60°C for 10 min was as efficient as the general decolorization (boiling in 10% NaOH for 20 min), and was carried out faster and safer than the general method. In addition, the microscopic observation by polarized light allowed easy identification of hairs (trichomes) characteristic in cannabis. Using a 96-well plate allowed to examine many samples at the same time. By the combination of color reaction with Fast Blue B, this method can be applicable to identification and discrimination of a large number of samples as a screening test.

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  We previously developed a rapid method for morphological examination of cannabis and its related herbal products. In this study, general methods for chemical examination by thin layer chromatography (TLC) and gas chromatography/mass spectrometry (GC/MS) were improved. In TLC, a development using toluene-hexane-diethylamine (25:10:3, by vol.) at 40°C allowed sufficient separation of cannabinoids and rapid analysis. It was also confirmed that the TLC conditions were applicable to the discrimination of cannabinoids and the other components in herbs. In the pretreatment for GC/MS, using a 96-well plate and a multi-channel pipette allowed to prepare many analytical samples at the same time. In GC/MS, using a short and narrow bore capillary column allowed rapid analysis (ca. 10 min/sample). Based on the chemical examination method in this study and the morphological examination method that we previously developed, a rapid procedure to examine cannabis and its related herbal products was proposed. In the morphological and chemical examination methods that we developed, the total time required for morphological examination by microscopy, color test by Fast Blue B reagent, and chemical examination by TLC was approximately 3 h for 96 samples.

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  Chiral analyses of methamphetamine (MA) and its metabolites of urine samples from 250 d-MA abusers were done by capillary electrophoresis/mass spectrometry (CE/MS) with direct injection of urine. We examined the relationships between the concentrations of unchanged MA and metabolites including the conjugates and the intake situations of MA (e.g. date, route) based on statements of abusers.

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