Obliterated Serial Numbers in Firearms
A report released by The National Institute of Justice gives a different way to detect compromised serial numbers on firearms. The two most used ways for restoring serial numbers is MPI and chemical etching. These technologies were compared to magneto optical (MO) sensor technology. This comparison revealed that MO sensor technology is a viable and reliable serial number restoration technique. This technique doesn’t damage the sample. Its also safe to use and easy. Also compared to the other technologies it did better in sensitivity, specificity, accuracy, and precision. The MO sensor technology works with multiple layers called wafers. It works by passing polarized light from a light source under influence of an external magnetic field. The light is reflected by the mirror layer after crossing the MO active film (layer). An analyzer eliminates all non‐altered components of the mirrored light beam. The result is a colored image of all magnetic fields over the sensor area where a camera records the image. The draw back of this technology is that it can only be used on flat surfaces and it is more expensive. But because of its positives it can be used as a fall back plan to investigators.
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Source: Forensic Magazine
[Abstract written by Alicia Terrell, ForensIQ Intern, 050814]
