Forensics Scenario Discussion From the Onset, it

Forensics

Scenario Discussion

From the onset, it is important to note that in criminal investigations, one type of evidence commonly encountered is hair evidence (Oien, 2009). As Oien further points out, "during the course of the normal hair-growth cycle, hairs are readily lost from individuals, and these hairs may be transferred during the course of a criminal activity." The hairs collected from the seat of the car in the scenario recounted could have, therefore, been transferred during the commission of the said criminal activity. However, the hairs could have come from either a human being or an animal. In that regard therefore, further analysis and comparison would have to be made to determine their origin.

To begin with, in my analysis, I would start by examining the medulla. According to Merck (2012), while the medulla of animals is particularly thick, that of humans is characteristically thin. I would also expect that if the hair came from a human, then its medulla would be darker under transmitted light. The darker medulla in this case would result from the fact that it "is often filled with air, which provides an insulating layer and thus temperature control for the person" (Tobin, 2005, p. 105).

If the hairs came from a human, I would expect consistency in both color and pigmentation along the entire shaft length. Animal hair would exhibit what is referred to as banding. In the words of Deedrick and Koch (2004), "human hairs are generally consistent in color and pigmentation throughout the length of the hair shaft, whereas animal hairs may exhibit radical color changes in a short distance." Further, in my analysis, I would examine the roots of both hair samples. This is particularly important given that while variability is common in the roots of animals, animal hair root is in most cases club-shaped (Deedrick and Koch, 2004).

In Defense of My Trace Evidence

The analysis of hair samples cannot conclusively pinpoint hair as having come from one individual, and not any other. With that in mind, hair analysis provides only indirect information with regard to the circumstances that could have taken place after, during, or even before the commission of a criminal activity. Findings in this case could therefore be regarded circumstantial. It should, however, be noted that an analysis of hair samples provides a vast amount of information (both microscopic and macroscopic) that could be used as a basis for association (Deedrick and Koch, 2009). In that regard therefore, by virtue of being based on scientific observation that can be regarded objective, I would argue that my trace evidence provides strong inculpatory evidence.

Part 2

Arson Dogs vs. Chemical Sniffers

In my own informed opinion, based on extensive review of literature, the results of arson dogs are far much better than those of a chemical sniffer and as a result, arson dog findings should be allowed as evidence in court. As some stage, arson investigations involve the detection or collection of traces of accelerant. In this case, sniffers (portable vapor detectors) or arson dogs could come in handy. While chemical sniffers in this case are designed to detect particles or molecules in the air -- hence helping in the identification of areas and instances where accelerants may have been used, arson dogs are trained to sniff out accelerant traces.