National Institute of Legal Medicine and Forensic Sciences - North Branch, Porto, Portugal.
Forensic Sci Int. 2013 Sep 10;231(1-3):244-8. doi: 10.1016/j.forsciint.2013.05.015. Epub 2013 Jun 25.
Identification of tool class characteristics from cut marks in either bone or cartilage is a valuable source of data for the forensic scientist. Various animal models have been used in experimental studies for the analysis of individual and class characteristics. However, human tissue has seldom been used and it is likely to differ from that of non-humans in key aspects. This study wishes to assess how the knife's blade angle, and both intra- and inter-individual variation in cartilage samples affect the ability of costal cartilage to retain the original class characteristics of the knife, as measured microscopically by the distance between consecutive striations. The 120 cartilaginous samples used in this study originated from the ribcage of 6 male cadavers which were submitted to autopsy at the North Branch of the National Institute of Legal Medicine, in Portugal. Three different serrated knives were purchased from a large department store, and were used in the experimental cuts. Samples of costal cartilage from 2 individuals were assigned to each knife. Each individual provided 20 cartilage samples. Cartilage samples were manually cut using each of the three knives, following two motions: one straight up-and-down cutting motion and parallel and one perpendicular to the blade's teeth long axis forward cutting motion. Casts of the samples were made with Mikrosil(®). Image capture and processing were performed with an Olympus stereomicroscope and its software. The blade's penetration angle and inter-individual variation were shown to affect the identification of the tool class characteristics from the striation pattern observed in a kerf wall, although this seems to be related only to the degree of calcification of the costal cartilage. Intra-individual variation does not seem to significantly affect the identification of the tool class characteristics from the striation pattern observed in a kerf wall, for the same knife following the same motion. Although this study did not quantify the degree of calcification of the cartilage, this seems to be an important source of great variation regarding the interpretation of striation pattern in cartilage.
从骨或软骨中的切割痕迹识别工具类别特征是法医科学家的宝贵数据来源。各种动物模型已被用于实验研究，以分析个体和类别特征。然而，人类组织很少被使用，而且在关键方面可能与非人类组织不同。本研究旨在评估刀的刀刃角度，以及软骨样本中的个体内和个体间变异如何影响肋软骨保留刀具原始类别的能力，这是通过连续条纹之间的距离在显微镜下测量的。本研究使用的 120 个软骨样本来自葡萄牙国家法医研究所北部分支提交尸检的 6 名男性尸体的肋骨。从一家大型百货公司购买了三把不同的锯齿刀，并在实验切割中使用。从 2 个人中为每把刀分配了肋软骨样本。每个人提供了 20 个软骨样本。使用三把刀中的每一把手动切割软骨样本，遵循两种运动方式：一种是直上直下的切割运动，另一种是平行于刀刃齿长轴的向前切割运动和垂直于刀刃齿长轴的向前切割运动。使用 Mikrosil（®）制作样本的铸型。使用 Olympus 立体显微镜及其软件进行图像捕获和处理。尽管这似乎仅与肋软骨的钙化程度有关，但刀刃的穿透角度和个体间变异会影响从切口壁观察到的条纹模式中识别工具类别特征。个体内变异似乎不会显著影响从切口壁观察到的条纹模式中识别工具类别特征，对于同一把刀，采用相同的运动方式。尽管本研究没有量化软骨的钙化程度，但这似乎是解释软骨条纹模式时产生巨大差异的一个重要来源。
