GB/T 40991-2021Collecting and packaging methods for trace evidence (English PDF)

Foreword

This document is in accordance with the provisions of GB/T 1.1-2020 "Guidelines for Standardization Work Part

1.Structure and Drafting Rules of Standardization Documents" Drafting. Please note that some of the contents of this document may involve patents. The issuing agency of this document is not responsible for identifying patents. This document was proposed by the Ministry of Public Security of the People's Republic of China. This document is under the jurisdiction of the National Criminal Technology Standardization Technical Committee (SAC/TC179). Drafting organizations of this document. The Material Evidence Appraisal Center of the Ministry of Public Security, Beijing Municipal Public Security Judicial Appraisal Center, Guangdong Provincial Public Security Department, Wuhan Municipal Public Security Judicial Identification Center, Shandong Provincial Public Security Department Material Evidence Identification Research Center, Shanxi Provincial Public Security Department, Xinjiang Uygur Autonomous Region Public Security Department Material Evidence Identification Center, Kyrgyzstan Forestry Provincial Public Security Department Material Evidence Identification Center, Heilongjiang Provincial Public Security Department Criminal Technology Corps, Guangxi Zhuang Autonomous Region Public Security Department Criminal Science and Technology Research Management . The main drafters of this document. Zhu Jun, Guo Hongling, Quanyangke, Li Shenglin, Liu Weiguo, Zhang Hongqi, Hao Suyuan, Yang Yuefei, Guo Jisen, Xie Wenlin, Zhang Jilin, Li Hongsen, Liu Minghui, Liang Ying, Pei Maoqing, Chen Chengxian, Li Xin, Jiang Hua, Wei Chuice, Li Yunzhi, Zhang Dalei, Mei Hongcheng, Wang Ping, Li Juan, Liu Huijuan, Ren Li, Wu Mingjian. Extraction and packaging method of trace material evidence

1 Scope

China's national methods for collecting and packaging trace evidence. It covers fibres, glass, grease, metal, soil, explosive residue and flammable liquid residues among others. Trace evidence is the material transferred between people, objects and places in the course of an event, and its value in an investigation depends entirely on the integrity of the chain from the scene to the laboratory. Almost everything that destroys it happens in the first hour. Fibres are lost by handling and cross-contaminated by the investigator's own clothing; glass fragments are ground into dust; flammable liquid residues evaporate within minutes and are absorbed by plastic bags, which is why they must go into metal or nylon; explosive residues are present in nanogram quantities and are removed by any contact. The packaging is therefore as specified as the collection, and the standard exists because a sample collected wrongly cannot be corrected later - it can only be excluded.

This document specifies fiber, glass, grease, metal, soil, explosive residue, flammable liquid residue, shooting residue, paint, rubber Extraction and packaging methods of trace material evidence such as plastics and plastics. This document is applicable to the extraction and packaging of trace material evidence.

2 Normative references

The content of the following documents constitutes an indispensable clause of this document through normative references in the text. Among them, dated quotations Only the version corresponding to the date is applicable to this document; for undated reference documents, the latest version (including all amendments) is applicable to This document. GA/T 242 The terminology of physical and chemical examination of trace evidence in forensic science

3 Terms and definitions

The terms and definitions defined in GA/T 242 are applicable to this document.

4 Reagents and materials

4.1 Reagents The reagents include.

a) Ether (C4H10O, analytical pure);

b) n-hexane (C6H14, analytically pure);

c) Acetone (C3H6O, analytical grade);

d) Deionized water.

4.2 Materials Materials include.

a) Special tape for extracting trace evidence;

b) Special sampling table and special sample box for shooting residue;

c) Scanning electron microscope sample stage and conductive tape;

d) Diamond knife;

i) straws (glass straws);

j) Glass test tube or glass sample bottle;