Various TV shows and popular fiction in the last five, ten years have brought the subject of forensic science into the public eye. However, what many think is forensic science is merely limited to the Hollywood interpretation of it, with forensic scientists playing the role of police officers at the same time, spending half their time in labs and half their time dodging bullets.
In the broadest sense, forensic science means the application of science to law. It is developed as a way to help enforce criminal and civil laws in the society. The process of doing a forensic investigation, therefore, is actually highly sophisticated and requires extreme care.
When arriving at a crime scene, officers are responsible for preserving and protecting the area immediately. It is tremendously important to keep a crime scene as untouched as it can be. Too easy it is for a curious onlooker to tread on an apparently important piece of evidence, and reduce greatly the chances of finding the culprit.
Then, instead of picking up everything and examining it like they do on the TV shows, what needs to be done next is recording the scene in its untouched state. Photographs should be taken, and sketches should also be done to give accurate dimensions of the scene and location of objects. Notes should also be made to accompany these photographs and sketches.
Then, forensic officers need to adopt a systematic approach of screening the scene, so as to make sure that they don't leave out any vital piece of evidence related to the case. For example, they can divide the scene into different quadrants or zones and search each zone extensively one at a time. Alternatively, they can also adopt the so called 'grid method', starting from one corner of the room, then search though the entire room horizontally then vertically. A qualified forensic scientist should always have the skill to decide the best search pattern to use at a particular scene.
Any piece of evidence collected must then be individually packed and labelled, so as to prevent damage or cross-contamination through contact. Care should also be taken that when dealing with biological evidence such as blood or semen, paper bags should always be used instead of plastic bags in order to prevent, say, the growth of mould inside the bag due to the moisture. Standards or reference samples should be taken simultaneously from victims and suspects so as to compare the evidence to.
A crime laboratory is actually divided into many different units, each specialising in a particular area. The most basic units that a crime laboratory should have include the physical science unit, biology unit, firearms unit, document examination unit and photography unit. The units would all work together on a case and evidence found would be sent respectively to the relevant units for examination.
In more sophisticated crime laboratories, they often include other units such as toxicology unit, polygraph or lie detector unit and voiceprint analysis unit. Sometimes there would also be units specialising in areas such as forensic pathology, forensic entomology and forensic odontology. Different units are helpful in their own way towards solving a crime.
Contrary to popular belief, it is not the job of a forensic scientist to say if someone is or is not responsible for a crime. All they need to do is make reports on whether evidence match or not. Occasionally, forensic scientists are summoned to court to give expert testimony on things such as the significance of the findings, the procedures used and the error rates of such procedures.
Although perhaps not as glamorous or exciting as some might believe it to be, the subject of forensic science is still nonetheless very interesting and challenging. As the field develops and flourishes, police officers are becoming more and more capable of arresting the right people for a crime. What makes it even more satisfying is that the techniques can only become better and more refined over time.