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What happened ?

What happened ?. Is this a sexual assault （性侵犯） ? When did the sexual assault （性侵犯） happen? Who is the victim （受害者） ? Who is the suspect （嫌疑人） ? How to discover and find the suspect （嫌疑人） ?. Thirteenth chapter （第十三章）. Location & Collection & preservation of Forensic

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What happened ?

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  1. What happened ? • Is this a sexual assault（性侵犯）? • When did the sexual assault（性侵犯）happen? • Who is the victim（受害者）? • Who is the suspect（嫌疑人）? • How to discover and find the suspect （嫌疑人）?

  2. Thirteenth chapter（第十三章） Location & Collection & preservationof Forensic biological Evidence in sexual assault （性侵犯案法医物证的发现、提取和保存）

  3. Teaching contents 一.Introduction（概述） 二.Collection principle（提取原则） 三. approach to collection and preservation of evidence（提取和保存证据方法） 四.Collection of the rape evidence（强奸案物证的提取） 五.Preservation of Evidence（物证的保存） 六.Packaging & Storage of Evidence（物证的包装和储存）

  4. 一. Introduction（概述） A large number of cases involve sexual offenses（性侵犯）, making it necessary to examine（检验）items for the presence of seminal stains（精斑）.

  5. 一. Introduction（概述） The forensic examination（法医检验）of semen（精液）is a two-step process: 1. First, the semen must be located---crime sence（犯罪现场）; 2. Second, tests must be performed to prove its identity（身份）—it may even be tested for DNA---lab（实验室）.

  6. 一.Introduction（概述） If a suspect（嫌疑人）is established（确定）in a rape case, then reference samples（参考样本） should be collected from the suspect for Comparison（比对）. Foresic scientists（法医科学家）will perform to prove its identity(身份) ---Who is the suspect? --- Who is the victim?

  7. How to collect the evidence?

  8. 二.Collection principle（提取原则） • Not degradation and/or loss.（不损失） • prevention of contamination.（不污染) • Not destroy(不破坏检材)

  9. 三. approach to collection and preservation of evidence（提取和保存证据方法） • A deliberate approach （周到的方法） • methodical approach （系统的方法） • disciplined approach （受过训练的方法） approach to collection and preservation of evidence is essential to prevent its degradation and/or loss（降解和损失）.

  10. 四.Collection of the rape evidence（强奸案物证的提取） 1.sperm ’s Timeline of examination （精子检测时限）. 2.Rape investigation（强奸案调查）. 3. Aim of Rape investigation （强奸案调查的目的）. 4. Collection of the rape evidence（强奸案物证的收集）.

  11. 1. sperm ’s Timeline of examination（精子检测时限） （1） Living sperm may survive 4 to 6 hours in the vagina（阴道） of a living person. （2）sperm may be found in a living female （女性） for up to three days and occasionally up to six days.

  12. 2.Rape investigation（强奸案调查） （1）How long ago was the person raped（强奸）? （2）When did voluntary（自愿的）sexual Activity last occur ? （3）Blood（血样）is taken from any sexual partner （性伙伴）within 72 hours of the assault.

  13. 3. Aim of Rape investigation（强奸案调查的目的） （1） When dealing with sexual assaults, the police officer has ask a living victim（受害者）to provide the information which will help in collecting and preserving the pertinent（相关的）evidence.

  14. 3. Aim of Rape investigation （强奸案调查的目的） （2）The key to proper collection（适当的收集物证的关键）, preservation, analysis is open and plentiful communication between police officer, forensic scientists, and victim . This will make the most of the evidence which can break a case.

  15. 3. Aim of Rape investigation （强奸案调查的目的） （3）The police officer should remember that each crime scene is different and each crime scene is a learning process.

  16. 3. Aim of Rape investigation （强奸案调查的目的） （4）The police officer（警官）should also keep in mind（记住）that different crime labs（不同的犯罪实验室）may like their evidence collected in different manners（不同的方式）. This is why the police officer should not hesitate(犹豫) to call his crime lab if he has a problem on the collection or preservation of evidence.

  17. 4. Collection of the rape evidence （1） When the victim is alive, How to collect the evidence? ①the victim should be taken to the hospital immediately（立即）and the examination started as soon as possible （检验尽快进行）. ②Photographs（拍照）should be taken to document （记录）any injuries（损伤）which the victim received.

  18. （1） When the victim is alive, How to collect the evidence? ③oral（口腔）, vaginal（阴道）, anal （肛门）swabs （拭子）should be taken from the victim and air dried（空气干燥）in a moving air source as soon as possible. Why should we do these things as soon as possible ?

  19. Why should we do these things as soon as possible ? A.because the body begins breaking down the various components（成分）in seminal fluid（精液）through drainage （排泄）, enzyme activity（酶作用）, pH, etc.

  20. Why should we do these things as soon as possible ? B. the moisture（潮湿）in the swabs（拭子）allows microorganisms（微生物）to grow which can destroy（破坏）the evidentiary value （证据的价值）of the swabs.

  21. （2） When the victim is dead, Collection of Rape Evidence ①Before collection， Police officers take video（摄像）, photography（拍照）,Sketche（现场图）which are completed at the scene to illustrate（显示）relationships between articles of evidence .

  22. ②Note Taking Police officers must know the importance of taking notes from the time of arrival（抵达时间）. Note taking should be continuously updated（更新）during the course of the investigation.

  23. ②Note Taking Note Taking might include such factors as: • Victim and witness statements（受害人和证人的陈述） • Who was present at the scene？ （谁在现场？） • Lighting conditions （灯光情况） • Open doors and windows （门窗开启情况） • Odors（气味） • Signs of activity such as food preparation （活动征象） • Date and time indicators such as newspapers or mail（时间指示） • General descriptions of the scene and surrounding area

  24. ③When the victim is dead, Collection of Rape Evidence • Police officers should prioritize（优先次序） the order in which evidence is collected. Biological evidence, trace materials（痕迹物证）, and evidence of a fragile nature（易碎物质）should be collected first. • The use of an alternate light source (多谱段光源) may be necessary.

  25. Before collection, Police officers should wear the following articles: • paper body suit （一次性衣服） • Paper mask that covers nose and mouth（口罩） • Eye protection（眼罩） • Latex gloves （乳胶手套） • Sleeve protectors （袖套） • Shoe covers （鞋套） • Paper cap（帽子）

  26. While collection, Police officers should Note the following items: the name of the sex crime（案件名称） The site and time of collection （提取的时间和地点） Position of collection（提取的位置）

  27. While collection, Police officers should Note the following items: Name,number, shape,colour ,size of evidences （物品的名称、数量、形状、颜色、大小） Who collect items,Who prove process. （提取人、见证人） Methods of package and preservion （包装和保存的方法）

  28. Police officers must pay more attention to following note: Police officers should abidenationallaws and regulations（遵守国家法律和法规）when you perform public affairs..

  29. ③Which the rape evidence will be collected ? • Outer and undergarments（外、内衣）are placed in separate（单独）paper bags, while victim stands on a piece of paper. The paper is then folded and collected. • Bedding（寝具）or the object upon which assault took place should be submitted（呈交）to the lab.

  30. ③Which the rape evidence will be collected ? • Rape vicitim must be subjected to a medical examintion Collected items include： pubic hairs（阴毛）, vaginal swabs（阴道拭子）, blood, fingernail scrapings（指甲削刮碎屑）, clothing and urine（小便） • Suspect must also undergo（经受）an exam. Routine items collected include： clothing, hairs, penile swab（阴茎拭子）and blood samples（血样）

  31. Sample include： • Body fluid swabs（体液拭子） • Pubic hair （阴毛） • Vaginal/oral/anal swabs（阴道、口腔、肛门拭子） • Vaginal/oral/anal smear slides（阴道、口腔、肛门涂片） • Fingernail scrapings （指甲削刮碎屑） • Buccal swab for known DNA（口腔拭子） • bitemarks swabs （咬痕拭子）

  32. How to collect the rape evidence ?Collection Techniques（技术） • The importance of avoiding cross contamination（交叉污染）can not be overemphasized（过分强调）. The Police officers must ensure（保证）tools are clean and that gloves are changed between handling each sample.

  33. How to collect the rape evidence ?Collection Techniques（技术） • Collection methods differ depending on the type of evidence and the substrate（衬底，）【 upon which is unstained portions of the biological evidence】. It is preferable（更好的）to collect evidence in its original state（原始状态）. If the evidence is fragile（易碎的）or can easily be lost, the entire object should be collected and packaged, if size and circumstances permit.

  34. 五.Preservation of Evidence（物证的保存） From crime scene to forensic laboratory to courtroom, all evidence must be inventoried （详细目录）and secured（安全） to preserve（保存） its integrity（完整性）. Evidence admissibility（允许） in court is predicated（断定） upon an unbroken chain of custody（监护）. It is important to demonstrate（证明） that the evidence introduced at trial（检验） is the same evidence collected at the crime scene, and that access was controlled and documented（已记录）.

  35. 五.Preservation of Evidence（物证的保存） Most biological evidence is best Preserved When stored dry and cold.These conditions reduce the rate of bacterial（细菌） growth and degradation（降解）of DNA.

  36. 五.Preservation of Evidence（物证的保存） Inside the lab,DNA sample are either stored in a refrigerator at 4℃ or a freezer at -20℃. DNA sample may even be stored at -70 ℃.For long periods of time.

  37. 六.Packaging & Storageof Evidence（物证的包装和储存） • Biological evidence should be dried before packaging to minimize sample degradation. Packaging in paper is preferred（首选的）; • Liquid samples should be properly documented and packaged in sterile（消毒的）glass or plastic containers and refrigerated as soon as possible.

  38. 六.Packaging & Storageof Evidence（物证的包装和储存） Proper evidence packaging includes: • Appropriate packaging and labeling of all items • Each item properly sealed and marked • Correct and consistent information recorded on label and procedural documentation

  39. Preservation of Evidence tissure stains Body fluid swabs 4℃，cold -20℃，freeze Air dried 4℃， cold -20℃，freeze Air dried Ethanol fixation

  40. 谢谢

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