Tool Mark Identification

Frictionmarksabrasion marksandscratchmarks

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Unformatted text preview: on Mark.* © Precision Forensic Testing * Association of Firearm and Tool Mark Examiners Glossary 4th Edition Toolmarks ­ Impressed Impressed marks can be left by a variety of tools. The most common are bolt cutters, pry bars, chisels, and hammers. © Precision Forensic Testing Toolmarks ­ Impressed Impressed marks are mirror images of the tool that left the impression. Any imperfections in the tools surface will be imparted to the work piece and can be used for comparison and identification. © Precision Forensic Testing Toolmarks ­ Impressed Bolt cutters are another tool that leave impressed marks as they squeeze the material in the cutting process. © Precision Forensic Testing Toolmark ­ Comparisons Compressed marks from bolt cutters can be used for comparisons. The individual characteristics of the bolt cutter blades reproduce on the surfaces they come in contact with. © Precision Forensic Testing © Precision Forensic Testing Tools ­ Comparisons Toolmarks made by compression tools yield mirror images of the tool. Any defects on the surface of the tool will be transposed onto the surface of the item it comes in contact with. The overall size and shape of the imprint is measurable and a class characteristic of the tool. Stamp Stamped Impression © Precision Forensic Testing Toolmarks ­ Striated Marks produced when a tool is placed against another object and with pressure applied, the tool is moved across the object producing a striated mark. Friction marks, abrasion marks and scratch marks are terms commonly used when referring to striated marks.* * Association of Firearm and Tool Mark Examiners Glossary 4th Edition © Precision Forensic...
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This note was uploaded on 04/09/2011 for the course CHEM 4461 taught by Professor Max during the Spring '08 term at Lamar University.

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