Expert fire investigation requires excellent analytical skills and a solid knowledge of multiple sciences. But these factors are only part of the equation. Fire investigators must also possess data. And the better the data, the more dependable—and defensible—the results. Until recently, fire investigators were reliant upon photographs, diagrams, and tape or total station measurements. Now with the advent of high-definition 3D laser scanners on the scene, investigators can quickly capture millions data points at the push of a button. “It’s improved the accuracy of my work,” said Dr. John DeHaan, president of fire and explosion consultancy firm Fire-Ex Forensics Inc.
Laser scanning technology not only provides an enormous amount of highly accurate data but also makes the data usable through 3D point cloud processing and visualization software, which replicates the physical scene in a 3D virtual format. With the exact scene digitally preserved, fire investigators can focus their analytical skills and scientific knowledge on finding a defensible solution.
In fire and explosion investigation, identifying the point of origin is critical. “If I look at an explosion scene, for instance,” DeHaan said, “and I can see where the debris is and how far away it was from the center, I can better estimate where the center actually was, which is half the battle in an explosion.” Scan data and visualization software facilitate this discovery. “Having a three-dimensional map of the site is a tremendous advantage to testing various hypotheses,” DeHaan said. “What if here? What if there? That’s an important part of any forensic inquiry. Witnesses can be wrong. There may not be any witnesses. And so you’re looking at the physics of the forces that broke up the original target and then where those pieces ended up.”
The increasing sophistication of fire and explosion analysis demands comprehensive, accurate laser scan data. “Now there are a couple of programs that can take the measurement data and put it straight into computer models for fire progression,” DeHaan said. These programs not only model the pre-explosion release of gases and vapors but also re-create the path of the explosion propagation and the dynamics. “It’s just amazing,” DeHaan said. “And that wouldn’t be possible if you didn’t have laser scan technology to provide all that data—not just dimensions but shapes and surfaces and things like that.”
Today, top-notch fire investigation requires broad scientific knowledge, excellent analytical skills and exceptional data. “It isn’t good enough to come in and look at a couple of patterns and say, ‘Based on my opinion—you know, my knowledge and experience—the fire started here.’ That’s not good enough anymore,” DeHaan said. “Data is what the courts expect. And the better the data, the more they are going to appreciate the accuracy of the investigator’s work.”
For more information on 3D laser scanning technology, contact us.
About the author: Wendy Lyons is a freelance writer living in Canton, Georgia, and has a degree in journalism. Lyons was introduced to geomatics through her work as associate editor for the nation’s leading land surveying magazine.
