CSI And Explosives
How is evidence of an explosion collected in CSI?
The investigation of explosions are very difficult at crime scenes because generally you would expect that most, if not all, of the explosive has been consumed so the crime scene investigator must identify the source or the point of the origin of the explosion, and collect all debris at that origin. It must be packaged and sent back to the laboratory for analysis.
How is an explosive identified in CSI?
There are a variety of means for identifying an explosive. It obviously depends on the nature of the explosion and the explosive. There are techniques known as gas chromatography, thin layer chromatography, gas chromatography, mass spectrometry. These are very highly sophisticated analytical techniques. What they all have in common is high sensitivity because when an explosion occurs, not all of the explosive is generally consumed. So you're looking for very minute quantities of materials, which must be looked for with very high sensitive analytical technologies.
What is a 'taggant' and how would it help in CSI?
The concept of a taggant is a very interesting one. The thought is that if you could add some foreign substance to an explosive material, that when the explosion does occur those so-called taggants would then be found at the scene of the explosion and could easily be collected for further identification. However, in the United States and most countries of the world the concept of a taggant has not been accepted. I believe there's just one country in the world, in Europe actually, that uses taggants. So, it's a concept that has not yet met acceptance throughout the world.
How have investigations of explosions helped in historic CSI cases?
One of the most important aspects of such an investigation is identifying the components of the detonator. Clocks and watches and things of that nature will perhaps help pinpoint the origin of the maker of that explosive. A good example of collecting physical evidence at the scene of an explosion, that ultimately can lead to the identification of the explosive maker, was the Oklahoma City bombing carried out by Timothy McVeigh. At that bombing scene, investigators were able to locate the name of the truck that he used to load the explosives on. It was a Renault truck. They were also, as the investigation proceeded, able to find his fingerprints on a receipt for one of the components of the explosive. That's an important and interesting example of how physical evidence from a variety of sources can be used to pinpoint the identity of an individual who has caused an explosion.
