From the free PDF copy at the web page Strengthening Forensic Science in the United States: A Path Forward (2009)Links to an external site.: Chapter 5: Descriptions of Some Forensic Science Disciplines
From the free, downloadable resource at the web page Crime Scene Investigation GuideLinks to an external site.: Section C: Processing the Scene
The videos Evidence and Forensics: Due ProcessLinks to an external site. and Forensic Science in Action: From Crime Scene to CourtroomLinks to an external site.
You are an intern at a forensic Crime Scene Response Unit (CSRU) and as part of your duties, the unit manager has asked you to develop a presentation on evidence for a Citizens’ Academy class. Develop a short presentation about the classification of evidence assigned. For this discussion forum evidence has been categorized into six types, although the evidence in each of these six categories could be further separated. You will be assigned topics by last name to complete this presentation.
T through Z: Combustibles and explosives
description of the type(s) of evidence included in this category
an overview of how that type of evidence emerged
how it was first used and any historical significance
current uses
how it should be documented
packaging methods
explanation of why this methodology is used
potential admissibility issues in court
Combustibles and Explosives Evidence
Description
Combustibles and explosives evidence is any physical evidence that is related to the use of fire or explosives. This type of evidence can include a wide variety of items, such as:
Overview
The use of fire and explosives as tools for crime has been around for centuries. However, the scientific study of combustibles and explosives evidence is a relatively recent development.
The first major breakthrough in the field of explosives analysis came in the late 19th century, when Austrian chemist Edmund R. von Hofmann developed a test for detecting nitroglycerin, a common ingredient in explosives at the time. This test, known as the Hofmann test, is still used today by forensic scientists to identify explosives residues.
Another major breakthrough came in the early 20th century, when American chemist William R. Brode developed a method for detecting gasoline and other petroleum products at crime scenes. This method, known as the Brode test, is also still used today by forensic scientists.
Historical Significance
Combustibles and explosives evidence has been used to solve countless crimes over the years. Some notable examples include:
Current Uses
Combustibles and explosives evidence is used in a variety of forensic investigations today, including:
Documentation
Combustibles and explosives evidence must be carefully documented at the crime scene. This includes taking photographs and videos of the evidence, as well as collecting samples of the evidence for analysis in the laboratory.
Packaging
Combustibles and explosives evidence must be packaged in a way that will prevent it from being contaminated or damaged. This typically involves packaging the evidence in airtight containers and labeling the containers clearly.
Methodology
The methodology used to collect and analyze combustibles and explosives evidence is constantly evolving. However, some common methods include:
Admissibility Issues
Combustibles and explosives evidence is generally admissible in court. However, there are some exceptions to this rule. For example, evidence that has been collected in violation of the defendant’s constitutional rights may not be admissible in court. Additionally, evidence that is not relevant to the case may not be admissible in court.
Conclusion
Combustibles and explosives evidence is a valuable tool for forensic scientists. This type of evidence can be used to solve a wide variety of crimes, including arson, bombings, and homicides. Forensic scientists use a variety of scientific methods to collect, analyze, and document combustibles and explosives evidence. Combustibles and explosives evidence