Analysis On Biological Evidence

With the explosive development of life science, more and more biological technologies have been applied to the field of criminal justice, which makes the application of biological evidence more common in criminal cases. But how to have correct cognition on biological evidence is the problem we first have to solve. The present study on biological evidence is mainly concentrated on human evidence in forensic science field, but less attention is given to evidence of plant and microbial evidence, and a lot of important biological evidence is not collected or destroyed due to the limited cognitive level of investigators. However, the detection of some difficult cases is often based on a major breakthrough on the biological evidence. The lack of standardization of extraction and preservation of blood evidence in the case of Simpson killing his wife made the criminal escape legal sanction; in the Huugjilt case the failure to identify seminal stain within the body of the victim although extracted and the losing of seminal stain in the court caused the occurrence of an unjust case; the Zhang nephew and uncle case in Zhejiang was exonerated owing to the vindication of DNA in the victim's nails with suspect's DNA in the database. The series of major cases are mainly related to biological evidence, making it urgent to the problems study related to biological evidence. This paper studies the biological evidence mainly from science of evidence, forensic medicine, and biology and focuses on the introduction to practical application of biological evidence in the investigation. This paper is divided into four parts:Part One discusses the basic meaning and historical origin of biological evidence. The current cognition of the biological evidence is limited to comparative analysis on the opinions of biological materials. This part proposes to incorporate the materials with biological characteristics into the category of biological evidence(such as the material with clearly identifiable traces left by animal feeding), and the new relatively complete concept of biological evidence in combination with biology, evidence of knowledge system. Subsequently, this part elaborates development and the latest trends of biological evidence in Chinese and foreign countries.Part Two expounds the common classification methods of biological evidence. In addition to animal, plant and microbial evidence according to the classification standard of the cellular structure, biological evidence can be classified according to the biological engineering technology and the spatial dimension standards. In the meanwhile this part mainly introduces the common types and characteristics of biological evidence.Part Three discusses the issues worth attention in the extraction and preservation methods of biological evidence. In combination with foreign experience and the provisions of Public Security and other departments on evidence collection, the author makes comprehensive introduction to extraction and preservation methods of biological evidence so as to ensure the complete chain of evidence and makes the systemic explanation to extraction, storage, inspection and review of blood, hair, saliva, semen stains, bone, animals, plants, insects, microorganisms, gas and other biological evidence common in the scene of the crime as well as biological hazards of the scene of the crime and protection on the investigators.Part Four elaborates the review and application of biological evidence. Combined with the knowledge of science of evidence and biosystematry, the author introduces separate, comparative and comprehensive review on biological evidence, researches species identification of biological evidence and the uniform identification in the separate review of biological evidence and simply introduces the identification of biological evidence. In addition, based on review on biological evidence, the author discusses the problems worth attention in the application and practice.