3D Laser Scanning
Written by Bob Cramblitt & Tony Grissim   

 

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3D Scanning:
Visualizing Scenes in Another Dimension

For many small to mid-sized agencies, 3D laser scanning technology may seem far out of reach—and maybe even unnecessary. But

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as the two case studies on these pages demonstrate, 3D laser scanning can speed up the documentation of even relatively simple crime scenes or accident scenes—and can prove to be invaluable at high-profile or particularly difficult-to-diagram scenes.

Case Study #1
3D Scanning at a Helicopter Crash in Germany

Written by Bob Cramblitt

COMPLEX INVESTIGATIONS often cannot be left solely to the powers of human observation. That is where 3D laser scanning and processing came into play for the Criminal Investigation Department in the Baden-Württemberg region of Germany. A recent helicopter accident investigation in the region provided an excellent example of the breadth of a scene that can be recreated with 3D laser scanning and modeling.

The scene of the accident was recorded by a 3D terrestrial laser scanner made by Zoller & Fröhlich, which has a range of up to 259 feet. The scanning device captured not only the helicopter, but also the surrounding topography, including trees that had been damaged by the crash.

Using the 3D laser scanner gave investigators an accurate way to digitally capture the entire accident scene with a high degree of accuracy.

This proved to be the critical first step in recreating the accident and determining a sequence of events that might have led to the crash.

Back in the lab, six scans totaling more than 50 million points were brought into Geomagic Studio software for processing.

Geomagic Studio is 3D software used to create digital models of physical objects. Product-development companies—including Ford, Harley- Davidson, Timberland, Fisher Price and many others—use the software to shorten a product’s time to market and to improve overall quality. The software is also used to capture large geographical areas for applications such as backdrops for motion pictures and digital preservation of historical structures such as the Statue of Liberty.

Within Geomagic Studio, the scan data from the accident scene was optimized to remove outliers, reduce noise, and fill in holes. Patented Geomagic technology was then used to align, merge, and register the multiple scan datasets and to create a polygon mesh. The final step was to modify, edit, and clean the polygon model. The Geomagic model of the scene gave investigators a digital replica of the damaged helicopter and the surrounding terrain, including measurement data that showed the extent of damage and the collision course.

The polygon model of the accident scene was brought into Autodesk’s 3ds Max 3D-animation software for further processing and animation. The completed scene in 3ds Max allowed investigators to “fly” around and view the accident from different angles. This provided a comprehensive view of the scene from angles that could not be accomplished with an on-site, physical investigation.

Along with other data and information, the animation helped investigators determine that the cause of the accident was pilot error.

“This 3D technology is an ideal aid and facilitator for our investigations,” said Sandra Petershans of the Baden-Württemberg Criminal Investigation Department. “Thanks to 3D scanning and processing, complicated objects that do not match common geometric shapes can quickly and easily be modeled and incorporated into animations, scene sketches, and reports.”

About the Author
Bob Cramblitt writes about design and engineering technologies that improve processes and transform human lives. He can be reached at: This e-mail address is being protected from spam bots, you need JavaScript enabled to view it


Case Study #2
3D Scanning of High-Profile Cases in Texas

Written by Tony Grissim

IT IS ONLY A MID-SIZED law-enforcement agency in a small Texas city, but in the past year, the Killeen Police Department (KPD) has found itself at the center of two very high-profile criminal investigations: the Fort Hood shootings on November 5, 2009, and the terrorist airplane attack at the Austin Internal Revenue Service (IRS) building on February 18, 2010. In both instances, the KPD deployed their Leica Geosystems ScanStation to document the scene.

Located just outside the gates of Fort Hood, the KPD acquired their Leica scanner with asset forfeiture funds in 2007 after Captain Jackie Dunn, commander of the criminal investigation division (CID), saw the ScanStation technology used on the A&E program Crime 360. Impressed by this innovative technology, Dunn brought it to the attention of Killeen Police Chief Dennis Baldwin, who immediately recognized its potential benefit to his agency.

The decision to purchase a Leica ScanStation is one those at the agency are glad they made, because it is making a difference not only in how much time crime-scene documentation takes, but also in the quality of the exhibits that can be produced.

“We are responsible for all of our own evidence collection and for processing the entire crime scene. Nobody comes behind us,” said Detective Keith Drozd. “Before we had the Scan-Station technology, it took us seven or eight hours to process a typical homicide scene using tape measures. Now we can do it in maybe three hours, tops. It has reduced a lot of our scene processing time. We can get back to the department and start talking to our witnesses and go from there.”

The agency’s success with the 3D laser-scanning technology has been recognized by those in neighboring jurisdictions, and has resulted in several calls for assistance in difficult, high-profile cases.

“At Fort Hood, their CID knew that we had the scanner and they checked with the FBI to make certain that they were OK with our deploying,” Drozd recalled. “When the call-out came, we deployed to the scene with the ScanStation within 20 to 30 minutes. We got there so fast that I had forgot-ten to grab my bullet-proof vest, and I had to borrow one, because at that point they weren’t 100-percent sure that there wasn’t a second shooter.”

The airplane attack on the Austin IRS building resulted in a crime scene that defied measurement by a tape measure or even a total station. A small aircraft had penetrated the side of a large government building. The resulting explosion and fire left a gaping hole and a huge debris field.

“I don’t know how a crime-scene unit could have documented that scene without scanning technology, but the ScanStation made it easy,” said Drozd. “With this device, mapping a scene like that is really nothing hard. It did a great job.”

An Austin-based employee of Leica Geosystems was also on hand to lend the KPD support if needed. 3D laser scanning has become such an important part of the Killeen Police Department’s investigative tool-box that they have recently reinvested in the technology by acquiring the newest version: the Leica Geosystems ScanStation C10.

About the Author
Tony Grissim is the public safety and forensic account manager for Leica Geosystems. He is a technical advisor for A&E’s television series Crime 360, as well as the Criminal Justice Program of Fox Valley Technical College in Appleton, Wisconsin. He can be reached at: This e-mail address is being protected from spam bots, you need JavaScript enabled to view it


ORIGINALLY PUBLISHED:
"3D Scanning: Visualizing Scenes in Another Dimension," written by Bob Cramblitt & Tony Grissim
September-October 2010 (Volume 8, Number 5)
Evidence Technology Magazine
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