Introduction
Tool marks are impressions or patterns left on surfaces by tools or instruments during various mechanical processes. These marks can provide valuable evidence in forensic investigations and can help identify the type of tool or instrument used in a particular crime.
Here are some different types of tool marks:
Cutting Marks
These marks are left by cutting tools such as saws, knives, or blades. They may appear as parallel striations or scratches on the surface, with the marks’ depth and spacing depending on the tool’s characteristics.
Also Read: Tool Marks Examination
Striation Marks
Striation marks are fine parallel lines or grooves left by tools that have a ridged or serrated surface. They can be found on materials such as metals, plastics, or wood, and they provide information about the type and size of the tool used.
Puncture Marks
Puncture marks are caused by pointed or sharp tools like nails, drills, or awls. They are characterized by a central depression or hole in the surface and may have distinctive features based on the shape and size of the tool.
Impressions
Tool impressions are three-dimensional imprints left on surfaces. They can include patterns from objects like pliers, wrenches, or vise grips. Impressions can reveal details about the texture, size, and shape of the tool, allowing investigators to compare them to known tools.
Striations on Bullets and Cartridge Casings
Firearms leave unique markings on bullets and cartridge casings when they are fired. These striations are caused by the unique patterns present in the barrel of each firearm and can be analyzed to match bullets or casings to a specific weapon.
Drag Marks
Tool drag marks occur when a tool is dragged or scraped across a surface. They can provide information about the direction, angle, and pressure applied during the tool’s movement.
Burnishing Marks
Burnishing marks are produced when a tool or instrument is rotated or rubbed against a surface with force. These marks often result in a polished or shiny appearance on the material and can be helpful in identifying the type of tool used.
