A Quick Tip for Creating More Useful Courtroom Exhibits
If your agency is laser scanning incident scenes, you have the ability to create state-of-the-art exhibits that enhance understanding and facilitate justice. But yet another level of context can be provided by incorporating scan data with other forms of geospatial information.
“I try and use all the tools in my geospatial tool bag—meaning GIS, GPS, laser scanning and, as needed, hand-recorded information—and combining it into as powerful an exhibit as possible,” said Ryan Rezzelle, CSI Section Supervisor of the Johnson County Sheriff’s Office Criminalistics Laboratory in Olathe, Kan.
Rezzelle’s CSI team utilized this geospatial-data-integration technique to provide context on a fatal case that occurred along a featureless stretch of Kansas highway. The incident, which is the focus of a previous article, began as a fistfight in a moving vehicle that transitioned onto a highway shoulder and spilled over the side of a hill. At the bottom, one man lay dead.
To document the scene, the team deployed its Leica ScanStation to scan the car, the shoulder and the hillside, and uploaded the data into Leica Cyclone 3D point cloud processing software. The most valuable exhibit, Rezzelle said, comprised cutaways captured within the Cyclone workspace. These 3D side views—showing the topography of the hill, the degree of slope and the distance the men traveled over the drop—provided the perspective needed to understand the spatial relationships and, ultimately, the mechanics of the fall and how the descent contributed to the fatal blow to the heart, which the coroner determined as the cause of death.
But the team wanted to provide even more context to the location of the event. “If you were to look at that data alone from a top-down perspective,” Rezzelle said, “you’d have no idea where in Johnson County you were.” The rural setting, he explained, lacked landmarks to readily identify the scanned area with a particular location. So the team accessed AIMS (Automated Information Mapping System), Johnson County’s online repository of geographic information system (GIS) data, and pinpointed the exact location using aerial photography found within the database. “I took the GIS photo—the overhead photo—of that roadway, dropped my overhead geoscan data into that GIS photo,” Rezzelle said, “and then built my site map around that so there was some perspective.”
As a result, the CSI team not only related perspective and the physics of the men’s fall down the hill but also—by integrating scan data with other forms of geospatial data—showed decision makers exactly where the incident occurred. “We could see where we were in space,” Rezzelle said, “and it became a more usable exhibit.”
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About the author: Wendy Lyons is journalist living in Canton, Georgia, who spent several years writing about surveying technology for POB magazine. She now focuses on covering laser scanning and other geospatial measurement solutions for public safety professionals.