Tool Mark Investigation Essay

Background:
The goal of this examination was to compare the suspect’s tools that were submitted to the markings that were found on seven (7) items of evidence. In order to determine if a tool that was submitted could have left a particular mark, class characteristics from both the tools and the mark were observed and recorded, as well as compared to one another in order to narrow down the list of potential tools that could have left a tool mark found on a given item of evidence. Some class characteristics that were measured from the tools submitted include, but are not limited to, distance between teeth marks, diameter of hammer face, length of hammer claws, length and width of plier jaws as well as the length and width of a wrench jaws, and the length and width of the cutting edge of the chisels. As mentioned previously, class characters were also recorded for the tool marks themselves. These class characteristics include, but are not limited to, measurements of the length, width and depth (if applicable) of the …show more content…
For example, a tool such as a hammer is not capable of squeezing to the same degree as, say, pliers are. Two of the biggest factors when determining the possible actions that could have caused a tool mark are identifying the type of tool mark left (impression or striation) and the shape of the tool mark. Looking back at our previous example, a hammer and a pair of pliers are both capable of leaving an impression tool mark. However, the most common type of action for a hammer is striking the face of the hammer onto the surface, causing a circular-shaped impression, while the most common type of action for pliers would be either gripping or squeezing, creating a rectangular-shaped impression that matches the dimensions of the jaw. One aspect to be careful of is to analyze the possibility of all possible actions that a tool can create, and not only the most