槍傷鑑定及彈道分析於偵查中之運用──以鄭性澤案與蔡學良案為例

Applications of firearm identification and trajectory analysis-Cheng Hsing-Tse and Tsai Shue-Liang cases

本報告以鄭性澤案與蔡學良案為例，評析其中槍彈鑑定證據研判之疑義，提醒大家，槍彈鑑定在發現事實真相之重要性。鄭性澤案之疑義有以彈殼位置研判射擊位置、以火藥射擊殘跡研判槍手、鄭性澤座位區之血跡型態、員警蘇 OO 陳屍區之血跡型態、蘇 OO 身上彈道、槍手在何處開槍襲警，另有法醫報告竟未列出蘇 OO 右手肘內側之槍傷之疑義等。蔡學良案之疑義有蔡學良持槍射擊姿勢、口含槍（口）管射擊、口含槍管槍管卻無唾液、有無火藥刺青痕、嘴唇區是否有 T65 步槍射入口槍傷型態、子彈鉛彈頭之鉛雪爆碎片是否為步槍槍擊特徵、蔡學良之槍傷是否符合 T65 步 槍射擊之槍傷特徵及是否為自殺之疑義等。

This report analyze the evidences of firearm and trajectory in Cheng Hsing-Tse and Tsai Shue-Liang cases on the value of finding truth. There are suspicious evidences such as, determining the shooter based on ejected shell and gunshot residues, bloodstain patterns on the floor of Cheng Hsing-Tse's position, bloodstain patterns on the floor of Su's body, trajectory in Su's body, shooting position and gunshot wound in Su's elbow. In Tsai Shue-Liang case, there are issues of shooting manner, intra-oral gunshot wound, no saliva on the barrel, tattooing on face, entrance pattern of rifle T65 on mouth, lead snowstorm in head, gunshot wound pattern of rifle T65 and suicide.