Toolmarks

This section details how to properly locate, document, collect, label, package, store, and preserve toolmark evidence during fire scene evidence collection and for subsequent use in testing or legal proceedings. Toolmark evidence has two basic forms: a known tool and an unknown mark. A known tool is collected to compare the characteristics of its working surfaces to unknown marks to see if the tool made that mark. Unknown toolmarks are collected or cast for comparison to known tools and related analyses. Locks and keys are also classified as toolmark evidence. Which fire scene evidence collection procedure to use for toolmarks evidence depends on whether it is a tool or a mark and what the mark is made on. Tools can typically be collected by hand. Locks are commonly cut out of the door or other object they are part of if the object is too large to collect. Toolmarks are commonly cast using a medium if they are on an object that cannot be collected, or they may be cut out of that object provided a large margin can be left around the toolmark so it is not damaged by the collection. Toolmarks may include other evidence embedded in or around the mark, like paint, fiber, hair, blood, or DNA. Collecting, packaging, and transporting toolmark evidence must be done properly or the tool working surfaces may be damaged and therefore no longer suitable for comparison and/or the mark can be altered or obliterated. Follow the procedures in this section to implement toolmarks and fire scene evidence collection best practices. If you are unsure which fire scene evidence collection procedure to use for toolmarks evidence or do not have sufficient experience to execute the procedure, consult your laboratory prior to collection.

 

Select a type of evidence to review its collection and packaging procedures.

Remember to also review the Checklists prior to collection and prior to releasing the scene.