羅卡定律，Locard exchange principle, Locard's theory，是法國法醫學家、犯罪學家埃德蒙·羅卡（Edmond Locard）創建的理論，對法醫學的發展作出了重要貢獻。
基本介紹
- 中文名：羅卡定律
- 外文名：Locard exchange principle, Locard's theory
- 別稱：羅卡交換定律
- 提出者：埃德蒙·羅卡
- 提出時間：1910年
- 套用學科：法證學
原理簡介,詳細內容,相關,
原理簡介
羅卡定律（英文：Locard exchange principle, Locard's theory），也稱羅卡交換定律，是法國法醫學家、犯罪學家埃德蒙·羅卡（Edmond Locard）創建的，其理論在於“凡兩個物體接觸，必會產生轉移現象”（with contact between two items, there will always be an exchange）。其用於犯罪現場調查中，行為人（犯罪嫌疑者）必然會帶走一些東西，亦會留下一些東西。即現場必會留下微跡證
詳細內容
“他站過的所有角落，他碰過的所有器物，他留下的所有東西，即使他毫無意識，也會留下一個對抗他的沉默證人。不僅僅是他的指紋和腳印，他的頭髮、他衣服上的纖維，他碰碎的玻璃，他留下的工具，他颳去的塗料，他留下或採集的血液或精液。這些種種或者更多，都支撐著對抗他的沉默見證。這些證據不會被忘記，不會被某一時刻刺激而變得渾濁，它不會因為人證而消失。它是事實存在的證據。物理性證據是不會有差錯的，它不會做偽證，它不會完全消失。只有對其尋找、學習和理解的人為錯誤，才會減損它的價值。
-- Paul L. Kirk. 1953. Crime investigation: physical evidence and the police laboratory. Interscience Publishers, Inc.: New York.”
碎片或微量跡證（trace evidence）是一種犯罪現場的物體存留或物體消亡調查方式，其中包括對鞋或者地板覆蓋物、土壤或纖維等外來物。
在實踐操作中，從犯罪現場提取的碎片或微量跡證可以用來指證罪犯罪行。通常由法醫或警察進行現場提取，有時需要對現場、被害人或其他證據進行攝像記錄或照片拍攝。如果必要，彈道檢驗（主要是彈痕）也可能進行提取。
相關
A law reveal the inevitable:
where the two objects contact will create a transfer phenomenon. Will take away some of the things, also left some things. - The father of forensic Rocca who will be left behind traces through. - The father of forensic pilocarpine
一條定律，道破必然
凡兩個物體接觸，會產生轉移現象。即會帶走一些東西，亦會留下一些東西。
——法證之父羅卡
凡走過必留下痕跡。
——法證之父艾德蒙·羅卡 The Locard exchange principle, also known as Locard's theory, was postulated by 20th century forensic scientist Edmond Locard.
Locard was the director of the very first crime laboratory in existence, located in Lyon, France. Locard's exchange principle states that "with contact between two items, there will be an exchange" (Thornton, 1997).
Essentially Locard's principle is applied to crime scenes in which the perpetrator(s) of a crime comes into contact with the scene, so he will both bring something into the scene and leave with something from the scene. Every contact leaves a trace.
“ Wherever he steps, whatever he touches, whatever he leaves, even unconsciously, will serve as a silent witness against him. Not only his fingerprints or his footprints, but his hair, the fibers from his clothes, the glass he breaks, the tool mark he leaves, the paint he scratches, the blood or semen he deposits or collects. All of these and more, bear mute witness against him. This is evidence that does not forget. It is not confused by the excitement of the moment. It is not absent because human witnesses are. It is factual evidence. Physical evidence cannot be wrong, it cannot perjure itself, it cannot be wholly absent. Only human failure to find it, study and understand it, can diminish its value. ”
—Professor Edmond Locard
1910 年，法國警官艾德蒙羅卡建立了一套黃金定律，那就是人類無論做過何種接觸，一定會留下微跡證。他的報告奠定了現代刑事鑑識科學的基石
利用羅卡的原理，刑事鑑識人員分析犯罪現場所發現的纖維，就可查出大量線索，如衣服款式、衣服售出地、甚至連織品製造商都可以查出來。藉由分析微小的纖維，微跡證鑑識員能夠確切指出嫌犯曾身處現場，進而定罪嫌犯。
《法證先鋒2》的第2集、第14集、第25集,《法證先鋒3》第9集都曾經提到過。
