In a series of random murders and gang rapes, biological material left at the crime scene was often a mixture from two or more individuals. In such cases, it is difficult to identify the DNA profile of each individual. Therefore, using the MCAR method, we aimed to detect the individual components of such a mixture for DNA typing, thereby establishing a method of examination that facilitates personal identification from a mixture of biological samples.
  In this study, we attempted to establish a method for the preparative separation of cells using laser microdissection (LMD), and determined the number of cells required for DNA typing. In addition, we investigated whether it is possible to determine the DNA profile of the cells separated from an experimental mixture of blood.
  As a result, we found that at least 16 cells were required for DNA typing by cell smear-LMD method. On the other hand, 150 cells were need for DNA typing by cell transfer-LMD method. In the case of a mixture of blood group A and B cells, it was possible to determine the DNA profile of each individual by the preparative separation of cells in positive regions with anti-A or anti-B antibody using MCAR and LMD.
  Biological material at the crime scene is almost always collected on a piece of gauze or adhesive tape, and for these cases, it is necessary to use the cell transfer method. In this study, it was suggested that the cell transfer-LMD method was expected in forensic application.
  However the mixtures are variously mixed with a great variety of cases for every sample, and are on various carriers. So we need to identify the exact location of the individual component and to take notice of biological contamination on carriers.

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  The Concealed Information Test (CIT), a polygraph test procedure that is adopted in Japan, is a memory detection method based on psychophysiological responses to critical questions. In this study, external validity of CIT experiments was examined by meta-analysis comparing electrodermal activity between mock-crime studies and field studies conducted in Japan. Literatures were searched using the following methods. (1) By referring to lists of journals that are reviewed in the CIT. (2) Computer searches of “Science Direct (http://www.sciencedirect.com/)” and “CiNii (http://ci.nii.ac.jp/)” databases. (3) Manually searching academic journals related to experimental, or criminal psychology. Meta-analysis by mixed effects model showed an overall average effect size of d 2.59 and 95% Confidence Interval (CI) [2.07, 3.11]. Nine mock-crime studies (n=187) showed an average effect size of d 2.35, 95%CI [1.77, 2.93], and 4 field studies (n=116) showed an average effect size of d 3.16, 95%CI [1.99, 4.33]. Furthermore, 3 field studies, without 1 field study as an outliner, showed an average effect size of d 2.47, 95%CI [1.67, 3.26]. Moreover, statistical hypothesis testing of the funnel plot indicated that there was no publication bias in these CIT studies. Furthermore, statistical sensitivity analysis indicated the reliability of the results of the meta-analysis. These results of the meta-analysis indicated that each 95%CI of mock-crime experimental studies and field studies had a considerable overlap, and there were not significant differences in effect sizes between both kinds of studies. It is concluded that electrodermal activity in mock-crime studies have adequate external validity.

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  Characteristics of male offenders arrested in Japan for exhibitionism (N = 414) and features of their offences were investigated. In analyses, their behavioral consistency was also examined by focusing on 87 repeat exhibitionists. The results indicated that many offenders were well-adjusted persons: 71% were employed, 30% were married, and 23% were graduates. Moreover, 66% of the offences were committed in daytime, and 64% targeted victims aged 10-20 years. In 24% of cases, the distances between offenders' residences and crime scenes were less than one kilometer, whereas 40% of offenders lived over 5 kilometers away. In terms of behavioral consistency, offences in “trains or buses” and public spaces were shown to be consistent for repeated arrests, even after taking the occurrence rate into consideration by measures of adjusted standardized residual (ASR) and forward specialization coefficient (FSC), which is suggestive of behavioral consistency. Finally, less frequent behaviors, such as nighttime offences and offences targeting victims aged 30 years or older occurred less consistently in the series of offences. The results suggested that many exhibitionists rationally decided when and where to commit crimes, based on their calculation of risk and reward. The fact that many offenders were well-adjusted persons might be one of factors explaining offender's rational decision making. The findings in the current study can contribute to the police investigation to prioritize their investigative targets. The current research can form the basis of understanding of the nature of male exhibitionists.

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  The objective of this study was to identify patterns of modus operandi that would be effective for predicting offender characteristics. For this purpose, logistic regression models were developed based on offender characteristics (17 variables) and modus operandi (50 variables) related to burglaries of residences, by using a stepwise method. Useful models were selected by using the area under the ROC curve, and by improvements in prediction accuracy from the prior probability, based on the frequency of the category of each offender characteristic. Models containing the following four offender characteristics were selected as useful: age, presence of a co-offender, criminal history of house burglaries with no one home, and criminal history of house burglaries late at night. Burglary experiences and age emerged as common potential factors of modus operandi and offender characteristics. It is suggested that selected modus operandi could be utilized to predict offender characteristics.

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  DNA typing of samples obtained from crime scenes can be used to identify suspects. However, samples obtained from sex crimes are often mixtures, and it is difficult to separate these for DNA typing. We extracted sperm from mixed samples using an ultra-high-speed cell sorter and examined whether DNA typing was possible. Propidium iodide was able to react with semen, allowing sperm nuclei to be sorted with the cell sorter. DNA typing was performed using the sorted sperm. The utility of anti-sperm antibody for cell sorting was compared with that of anti-sperm surface protein SP17, and anti-sperm antibody was found to be more suitable. Thus, semen reacted with anti-sperm antibody and with propidium iodide, thereby allowing sperm with nuclei to be collected. DNA typing could then be performed using the sorted sperm.

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  Direct amplification of short tandem repeats (STR) locus from reference sample without DNA extraction, quantification and dilution processes is one of the solutions to achieve a large amount of DNA profiling quickly. Therefore, in this study, AmpFℓSTR Identifiler Direct Kit (IDD) was tested in the laboratory of the National Police Agency.
  Buccal cells from 88 volunteers self-collected by using the EasiCollect device were transferred on FTA cards. One disk (φ1.2 mm) is punched from each of the 88 FTA cards and automatically distributed to PCR plates by BSD 1000. The optimal PCR cycles were examined using the PCR plates. PCR plate setup, capillary electrophoresis (CE) plate setup and CE were performed by Biomek FX^P, Biomek 3000 and 3130xl Genetic Analyzer, respectively. The threshfold of peak detection was set as 150 relative fluorescence units (RFU), and all other conditions of electrophoresis and analysis were used according to the manufacture's recommendations.
  Number of proper full profiles obtained from 88 samples were 68 (77.3%), 33 (37.6%), 14 (15.9%) and 3 (3.4%) for 25, 26, 27 and 28 cycles PCR, respectively. Therefore, 25 cycles PCR was optimal for our laboratory. The 68 proper full profiles obtained with 25 cycles PCR were used for validation study. Average of peak height and heterozygous peak height ratio of each STR locus were 1000-2000 RFU and 90% or more, respectively. Intra-color balance and inter-locus balance were almost the same as those in previous study with AmpFℓSTR Identifiler Kit (ID), AmpFℓSTR Identifiler Plus Kit (IDPlus) and IDD. When a threshold value of 150 RFU was applied with the “marker-specific stutter ratio”, proper STR typing was possible.
  Our study indicated that IDD with 25 cycles PCR was applicable to STR typing of single-source buccal cells transferred on FTA card in our laboratory.

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  A hollow core fiber was utilized as a capillary flow-cell for the infrared spectroscopy in gas phase that has the 1 m optical length and requires the sample volume of 2 ml. The system was applied to the qualitative analysis of hydrochloric acid. As a result, the specific spectrum of hydrochloric gas was successfully obtained at 10 times higher absorbance compared with an ordinary gas cell with 10 cm optical length. The capillary flow cell system developed in the present study can be a powerful tool in forensic chemistry for the analysis of hydrochloric acid and other volatile toxic substances.

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