Glass and Soil Evidence, Essay Example

In the context of Glass and Soil Evidence the term ‘physical property’ means having the physical property of the substance without changing its composition through chemical reaction.  ‘Chemical property’ means that the physical property of the substance has had its chemical composition modified for analysis and testing purposes. It is essentially the behaviour of that substance and how it reacts with another chemical property.

Soil Samples

Soil samples were examined at crime scenes as early as the 19^th Century. It included the collection of trace samples of a number of substances which includes items such as hair, blood, dirt, fibres, glass and other small particles retrieved from the crime scene. Forensic scientists examine these particles in an attempt to trace the location of where a victim has been; the soil samples may be mineral, organic or synthetic by nature.  A famous investigation by the FBI Forensic team was that of the Enrique Camarino case where the located the site of the victims by hair, fibre and soil samples.  Despite tampering and corruption within the Mexican police authorities the FBI were able to secure a successful conviction.

Glass Samples 

Glass is primarily composed of silicon dioxide and can be readily identified by its varying mineral decomposition i.e. soda lime, lead, borosilicate and other special properties. The glass can be collected from a crime site and the tiny fragments used for matching with other particles that might be found on the suspects clothing. This occurrence needs to happen fairly rapidly after the crime taking place as statistics indicate that 90% of particles are shed from clothing within a 24 hour period.  (Cengage, G. et al 2006)

Glass particles are difficult to analyse and this evidence is not as reliable as that of DNA testing. It is useful in the context of an additional piece of evidence when putting together a complete diagnostic analysis of the crime scene to potential suspects.

Works Cited

Cengage, L. L. (2006). “Glass.” World of Forensic Science. Retrieved 5 31, 2011, from e-notes: http://www.enotes.com/forensic-science/