From any crime show that we’ve viewed on television or in the movies, there is that moment where the evidence matches and the suspect is then brought to justice. They make it seem so easy and it only take a few moments. It’s definitely much more complicated than it looks and the forensic professionals who make that positive distinction are nothing less than exemplary in their work.
The microscope is the key piece of equipment in any forensic lab. It’s an optical instrument that uses a lens or a combination of lenses to magnify and resolve the fine details of a particular object of interest.
The earliest and most simple microscope with a single lens was the magnifying glass. Can you imagine trying to make sense out of a single hair or carpet fiber with just a magnifying glass?
Today, there are five main types of microscopes that are used most frequently in examining forensic evidence in crime scene investigations:
This microscope consists of a mechanical system that supports both the microscope and optical system. It illuminates the object and passes light through a series of lenses to form an image of the specific specimen as seen by the eye. There are a number of magnifying powers, such as 10x, 20x, 200x, or 450x.
This is a common microscope used in forensic labs because it offers a side-by-side comparison of specimens. It’s basically two compound microscopes combined into one unit. The unique feature allows it to use a bridge incorporating a series of mirrors and lenses to join two independent objective lenses into a singe unit. This microscope is effective in comparing bullets, hair, and fibers.
This type of microscope is used to characterize the structures of physical evidence that do not necessarily need a high magnification. It’s generally in the magnification range of 10x to 125x. It gives a distinctive three-dimensional image of the object. It is no doubt the most commonly used microscope in the forensic lab.
This type of microscope uses the polarizer by transmitting light vibrating in the vertical plane only. It’s similar to Polaroid sunglasses and it appears no different to the eye from ordinary light. The result makes the specimen readily distinguishable by allowing the polarized light to pass through the analyzer. It will then produce vivid colors and intensity in the contrasts, such as with soils and crystalline substances.
This microscope device is essentially combining and linking a new dimension of the computer to the microscope. It assists with visual comparison by enhancing color as with specimens such as paint, fiber, and ink evidence.
The next time you watch CSI, NCIS or any other crime dramas, see if you can pick out these types of microscopes that are used in the lab.
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Crime Watch Blog: www.emilystonecrimewatch.wordpress.com/
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