Analysis of Trace Characteristics Formed by Angle Grinder in Cable Theft Cases

Angle grinder is a tool used for grinding metal, wood, plastic and other materials. In recent years, it frequently appears in some cases of railway cabbe theft. Because the cutting marks formed by angle grinder are similar to saw tools, it is difficult to analyze and judge the types of tools in practical cases. In the paper, through simulation experiments, angle grinder and hacksaw were used to cut copper-core cables of different specifications, and the tool marks formed at the broken ends of cables were observed by microscope, to summarize the characteristics and differences of the tool marks formed by the two. It was found that the cross-sectional shapes of the cable broken end cut by angle grinder and hacksaw were similar overall, both of which were flat, but most of them were stepped by hacksaw, while those cut by angle grinder were smooth. Angle grinder will form parallel line traces with a certain radian at the section, while hacksaw will form multiple straight lines and cross each other. At the same time, there are differences between them in starting point trace, terminal trace and chip morphology. In actual case analysis, we should make a comprehensive judgment based on the cable broken end position, cable diameter and other conditions, and emphasize the differences in traces formed by angle grinder and saw tool. The research on the characteristics and formation mechanism of tool marks formed by tool marks formed by angle grinder cutting cables can provide certain theoretical support for judging the types of tools in related cases.