======Tool Mark Identification======


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**Alternative titles:** Forensic Tool Mark Comparison
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====Summary====                   
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====Procedure====  
  - Gather four tools, including two pairs of similar tools with slight differences (e.g., screwdrivers of different sizes).  
  - Roll out dark modeling clay or Play-Doh into a flat surface.  
  - Use one tool to make an **impressed mark** by pressing it into the clay.  
  - Use the same tool to make a **striated mark** by dragging it across the clay.  
  - Repeat with the other tools to create comparison samples.  
  - Have a partner secretly choose one tool from each pair and create both an impressed and striated mark in fresh clay to represent a “crime scene.”  
  - Examine the unknown marks and compare them to the known samples using visual inspection or a magnifying glass.  
  - Decide which tool made each mark, making at least one positive identification and ruling out at least one tool.  
  - Document findings with photos, sketches, and written notes.



====Links==== 
Collecting Impression Evidence, pry marks and tool marks - Michael McCutcheon: 
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📄 Tool Mark Identification & Analysis Activity - Cliffs Notes: [[https://www.cliffsnotes.com/study-notes/26913053]]\\


====Variations====
  * Test marks made in different materials, such as wax or soap.  
  * Use digital microscopes or cameras to enhance comparisons.  
  * Stage a mock “crime scene” where multiple students contribute tool marks for analysis.



====Safety Precautions====
  * Handle tools carefully to avoid injury.  
  * Supervise use of heavy tools such as hammers.




====Questions to Consider====
  * What is the difference between impressed marks and striated marks? (Impressed marks are indentations; striated marks are scratches or grooves made by movement.)  
  * Why is it important to test multiple characteristics of a tool mark instead of just one? (Similar tools may leave marks that look alike; detailed comparisons reduce error.)  
  * Can tool mark analysis always identify one specific tool? (Not always—sometimes it can only narrow down the possibilities.)  
  * How does this experiment model what forensic scientists do in real investigations? (They compare tool marks from crime scenes with suspect tools to determine matches or exclusions.)