CrimePsych

In the world of forensics there are an amazingly vast number of tests that can be conducted on a material in order to establish various things that may be useful in a trial. Listed below are just a few of the more commonly used techniques:

X-Ray Diffraction
The whole purpose of x-ray diffraction is to determine the atomic structure of a substance, but how does it work i hear you ask. By firing x-rays at a sample of the substance results can be recorded onto a sheet of photographic paper when said rays collide with the its own atoms.

The X-rays bounce off and form unique patterns on the photographic paper based upon the nature of the atoms they actually hit.

Electrophoresis
When it comes to DNA profiling there are a number of different procedures that can be conducted on biological matter in order to determine a genetic fingerprint. One of the ways that this biological matter is separated is through electrophoresis. Both blood and semen can be submitted to this process – it uses an electric current in order to separate the different sized molecules in proteins, enabling them to be submitted for further analysis.

Chromatography
There are a number of different methods that exist in chromatography, all of which are based around a similar scientific principle and all of which have been scientifically proven. It is primarily used to identify different chemicals as in dyes, drugs and residue found in dirt. It also has the ability to identify DNA, proteins and genes from tiny samples. At the end of the day the process is designed in such a way that it separates out the various components from each substance in order for them to be identified.

Spectrometry
After individual components of a sample have been separated is when this forensic method comes into its own. What it does is test a components light absorption and reflection qualities by by using a device called a spectrophotometer. By using this device, forensic experts are able to see exactly which colours of light are affected by a sample, and subsequently compare the obtained sample with samples of material they already have in their databases with results represented in graphs.

Mass Spectrometry
While it contains the title of the previous forensic technique, the actual methods utilised are completely different to its predecessor. Mass spectrometry uses high energy electrons in order to literally ‘knock’ electrons out of the samples molecules which in turn causes them to fall apart. After this process is completed a mass spectrometer uses an electrical or magnetic field to measure each individual pieces mass.

Particular molecules will always break into a predictable range of pieces with no chance that two different molecules will break into identical pieces. Given this, forensic professionals are able to take any sample of material and ascertain exactly what chemical components are within it.

Neutron Activation Analysis
This is one of the most amazing and accurate forensic techniques in the book – not that forensic techniques are ever inaccurate, but this particular method can detect whether atoms from a particular element are present in a sample down to levels as low as one part per billion. This particular forensic method exposes samples to gamma rays in order to look through to the centre of an atom within a sample thereby identifying what atoms are actually present. It is used to detect trace elements in not only drugs and gunpowder but also metals, paint, soil and hair.