A classification of deformed bullets, .38 (9 mm) caliber in size, determining by the length of the land and groove impression
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Abstract
This research aims to study: 1.) the average the length of the land and groove of approximately .38 caliber (9mm) bullets, and 2.) to classify the type and size of approximately .38 caliber (9mm) bullets that have been deformed bullets on the length of the land and groove. The sample used in this study consists of 60 deformed .38 caliber (9mm) bullets. The average the length of the land and groove obtained from the experiment will be compared with the opinions of examiner in Firearms and Ammunition Identification Sub-Division, Central Police Forensic Science Division, Office of Police Forensic Science. The tools used in this study include sample firearms and approximately .38 caliber (9mm) bullets, a comparison microscope, and bullet recovery. The statistical methods used for data analysis are the mean, percentage, standard deviation, and one-way analysis of variance (ANOVA). The study results show that, for each bullet size, at least one pair has a statistically significant difference in the average rifling groove length at the 0.05 level. This allows for the classification of approximately .38 caliber (9mm) bullets based on the length of the land and groove. Additionally, the classification matched the forensic examiner's identification of type and size in 11 samples, accounting for 47.83% of the total samples the examiner could confirm (27 samples). Furthermore, bullets from revolvers such as the .38 SPECIAL and .357 MAGNUM, which are typically difficult to distinguish, could be differentiated when jacketed (FMJ) due to an average groove length difference of up to 1.0 mm. This study demonstrates the practical application of land and groove impression measurements in forensic science to support the identification and classification of deformed bullets with improved accuracy.
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เนื้อหาและข้อมูลในบทความที่ลงตีพิมพ์ใน วารสารวิชาการอาชญาวิทยาและนิติวิทยาศาสตร์ โรงเรียนนายร้อยตำรวจ ถิอว่าเป็นข้อคิดเห็นและความรั้บผิดชอบของผู้เขียนบทความโดยตรงซึ่งกองบรรณาธิการวารสาร ไม่จำเป็นต้องเห็นด้วยหรือรับผิดชอบใดๆ
บทความ ข้อมูล เนื้อหา รูปภาพ ฯลฯ ที่ได้รับการตีพิมพ์ใน วารสารวิชาการอาชญาวิทยาและนิติวิทยาศาสตร์ ถือว่าเป็นลิขสิทธิ์ของวารสาร วารสารวิชาการอาชญาวิทยาและนิติวิทยาศาสตร์ หากบุคคลหรือหน่วยงานใดต้องการนำทั้งหมดหรือส่วนหนึ่งส่วนใดไปเผยแพร่ต่อหรือเพื่อกระทำการใดๆ จะต้องได้รับอนุญาตเป็นลายลักษณ์อักษรจาก วารสารวิชาการอาชญาวิทยาและนิติวิทยาศาสตร์ ก่อนเท่านั้น
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