著者

平川 俊介 案部 雄一郎 山下 珠希 内野 隆一郎 丸田 英基 才本 明秀 石松 隆和

出版者

日本法科学技術学会

雑誌

日本法科学技術学会誌 (ISSN:18801323)

巻号頁・発行日

vol.20, no.2, pp.125-140, 2015 (Released:2015-07-17)

参考文献数

15

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Handgun bullets fired toward the windshield of an automobile sometimes ricochets. In such a case, we must estimate the type of bullet and direction of shooting from the damaged windshield. The purpose of this study is to obtain a method to estimate the fired direction of a handgun bullet from the fractured windshield. We test fired bullets to an automobile windshield with various incidence angles. The thickness of the windshield is slightly different from model to model of the automobiles. In the beginning, we examined the strength of the automobile windshield of various car models. First, we examined the static failure strength of the windshield by an indentation test. In this test, fracture load and the amount of indentation were measured on windshield samples cut from ten models of Japanese automobiles. Next, we test fired a handgun in order to examine the relation between the trajectory of a bullet and the collision marks on the windshield. The cartridges used in these test firings were 38SPL. lead round nose (LRN) bullet and full metal cased (FMC) bullet. In the results of static indentation test for different car models, there was found to be almost no differences in the relationship between fracture load and indentation depth. With the LRN bullet, bullets perforated the windshield when the incidence angle was less than 45 degrees and ricocheted when the incidence angle was greater than 60 degrees. In these cases, a characteristic damage was left on the windshield. On the other hand, FMC bullets of 38SPL. perforated the windshield when the incidence angle was less than 60 degrees and ricocheted when the incidence angle was greater than 70 degrees. Based on these results, we proposed a method to estimate the direction of shooting in criminal cases in which a bullet was fired on an automobile windshield.

著者

平川 俊介 案部 雄一郎 山下 珠希 内野 隆一郎 丸田 英基 才本 明秀 石松 隆和

出版者

日本法科学技術学会

雑誌

日本法科学技術学会誌 (ISSN:18801323)

巻号頁・発行日

pp.687, (Released:2015-05-08)

参考文献数

15

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Handgun bullets fired toward the windshield of an automobile sometimes ricochets. In such a case, we must estimate the type of bullet and direction of shooting from the damaged windshield. The purpose of this study is to obtain a method to estimate the fired direction of a handgun bullet from the fractured windshield. We test fired bullets to an automobile windshield with various incidence angles. The thickness of the windshield is slightly different from model to model of the automobiles. In the beginning, we examined the strength of the automobile windshield of various car models. First, we examined the static failure strength of the windshield by an indentation test. In this test, fracture load and the amount of indentation were measured on windshield samples cut from ten models of Japanese automobiles. Next, we test fired a handgun in order to examine the relation between the trajectory of a bullet and the collision marks on the windshield. The cartridges used in these test firings were 38SPL. lead round nose (LRN) bullet and full metal cased (FMC) bullet. In the results of static indentation test for different car models, there was found to be almost no differences in the relationship between fracture load and indentation depth. With the LRN bullet, bullets perforated the windshield when the incidence angle was less than 45 degrees and ricocheted when the incidence angle was greater than 60 degrees. In these cases, a characteristic damage was left on the windshield. On the other hand, FMC bullets of 38SPL. perforated the windshield when the incidence angle was less than 60 degrees and ricocheted when the incidence angle was greater than 70 degrees. Based on these results, we proposed a method to estimate the direction of shooting in criminal cases in which a bullet was fired on an automobile windshield.

著者

伊藤 さよ 佐藤 高広 山下 珠希 鈴木 康弘

出版者

Japanese Association of Forensic Science and Technology

雑誌

日本法科学技術学会誌 (ISSN:18801323)

巻号頁・発行日

vol.19, no.2, pp.133-137, 2014

被引用文献数

1

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Glass fragments are valuable evidence in the criminal investigation of hit-and-run, murder and burglary cases. Screening of glass fragments should be carried out by refractive index (RI) measurement after the identification of unknown fragments of glass by analysis using electron probe microanalysis (EPMA), scanning electron microscopy with an energy dispersive X-ray spectrometer (SEM-EDS) and/or X-ray fluorescence spectrometry (XRF). However, it has been pointed out that RI values of glass fragments can be influenced by electron beam and/or X-ray of the instrumental analysis, although the effect of them on RI values of glass has not been sufficiently examined.<br>   In this work, we compared the RI values of glass fragments before and after irradiation by electron beam and/or X-ray using these devices. Glass fragments were collected from 3 different uses (windowpane of building, windshield and beer bottle). No significant difference was recognized in the RI values of these glass fragments before and after 30 minutes of irradiation.<br>   We have ascertained that the effect of electron beam and/or X-ray on the RI values is negligible in the conditions of the present study and that comparison of RI values is still useful for the forensic screening of glass fragments even after the instrumental analysis described above.<br>

著者

平川 俊介 案部 雄一郎 山下 珠希 内野 隆一郎 丸田 英基 才本 明秀 石松 隆和

出版者

Japanese Association of Forensic Science and Technology

雑誌

日本法科学技術学会誌 (ISSN:18801323)

巻号頁・発行日

2015

---

Handgun bullets fired toward the windshield of an automobile sometimes ricochets. In such a case, we must estimate the type of bullet and direction of shooting from the damaged windshield. The purpose of this study is to obtain a method to estimate the fired direction of a handgun bullet from the fractured windshield. We test fired bullets to an automobile windshield with various incidence angles. The thickness of the windshield is slightly different from model to model of the automobiles. In the beginning, we examined the strength of the automobile windshield of various car models. First, we examined the static failure strength of the windshield by an indentation test. In this test, fracture load and the amount of indentation were measured on windshield samples cut from ten models of Japanese automobiles. Next, we test fired a handgun in order to examine the relation between the trajectory of a bullet and the collision marks on the windshield. The cartridges used in these test firings were 38SPL. lead round nose (LRN) bullet and full metal cased (FMC) bullet. In the results of static indentation test for different car models, there was found to be almost no differences in the relationship between fracture load and indentation depth. With the LRN bullet, bullets perforated the windshield when the incidence angle was less than 45 degrees and ricocheted when the incidence angle was greater than 60 degrees. In these cases, a characteristic damage was left on the windshield. On the other hand, FMC bullets of 38SPL. perforated the windshield when the incidence angle was less than 60 degrees and ricocheted when the incidence angle was greater than 70 degrees. Based on these results, we proposed a method to estimate the direction of shooting in criminal cases in which a bullet was fired on an automobile windshield.<br>