Three-Dimensional Laser Scanning of Crime Scene Gum - Essay Example

The project does not include any form of contact and is nondestructive thus more efficient before extracting DNA from the gum. The theme of their research is that their method, which involves generating a digital file, could be used for dental comparison in the future in case the original chewed gum gets damaged by forensic analysis following 3-D scanning.

In their research, they used an automated 3-D laser scanner that ensures a reliable, affordable, and reproducible means for scanning a 3-D object fast and at a possible resolution of 127 microns. They scanned a piece of chewing gum that had been air-dried for 24 hours by placing it on the tip of a tuberculin syringe needle and then positioning it on the scanning stage of the laser scanner that is fully robotic. Using precise scan parameters of the laser scanner for a 360-degree scan, they used macro 0.005 inches precision, 125 seconds scan speed, and 0.005 triangle size. This process took less than three minutes given that they set the light in the color of the target surface to that of the matte finish, and the smoothing had auto-align of the eight segments on with a setting of 1.

After all the procedures involved in the process had produced digital files, they were able to come up with a virtual block that showed the shape and contours of the teeth impressions just like those in the original gum. They then used a Web-based prototyping service called Shapeways to order clear resin as well as white plastic models of the gum from their digital files. All this took less than 10 minutes, and they received the resulting plastic models of the chewing gum obtained from the digital files via mail within a few days and even took pictures to include in their report.

In their conclusion, the authors can illustrate that there is a quick and inexpensive procedure that can be used to scan gum found at a crime scene. They used a desktop, and a compact, automated 3-D laser scanner to create a virtual tooth imprint model with the use of the trueSpace CAD program. Using an online prototyping service, they managed to obtain a solid model of the gum they had scanned and uploaded to the website. According to the authors, the web-based rapid prototyping services are flexible, reliable, and easy to use once they uploaded the digital file. They also noted that combining these services may also provide a variety of uses fundamental in criminal investigations.