August 18, 2011 By Brian Heaton
CSI and Central Virginia may not come across as a flashy combination for a TV show, but some of the futuristic 3-D technology seen on the crime drama series is making an appearance in the Old Dominion state.
The Central Virginia Regional Crash Team received two Leica HDS4500 3-D scanners earlier this month that will be used to reconstruct three-dimensional models of traffic crashes and crime scenes in the central and southwest areas of Virginia. The models can be analyzed by forensics personnel to determine what happened at a scene and as evidence in court proceedings.
The scanners were a donation from Areva, a nuclear energy services firm. Capt. Jim Bennett of the Bedford Police Department and leader of the Central Virginia Regional Crash Team, said while the equipment is secondhand and about halfway through its life cycle, to purchase just one new 3-D scanner would cost approximately $120,000. So getting two was a great deal.
“It’s cheaper for us to repair and maintain these then to go out and purchase them new,” Bennett said. “State Police for Virginia has one and we have two, which is kind of cool [and] makes me feel we’re doing something right in Central Virginia.”
The Central Virginia Regional Crash Team is a multi-jurisdictional unit comprised of seven law enforcement agencies in the city of Bedford, Bedford County, Franklin County, the National Park Service, and the towns of Vinton and Rocky Mount.
Bennett said Areva is going to provide training to officers on the team on how to use the equipment. In addition, software will be purchased to fully take advantage of the 3-D technology.
Ultimately the plan is to officially put the scanners to work in October.
Bennett conceded they won’t be used to scan every crime or crash scene.
“We’re not going to break this out all the time because it’s so expensive and we don’t want to break it,” Bennett said with a laugh. “But if we have serious crimes and fatalities ... this is going to be the perfect tool for us.”
Benefits of 3-D
Currently members of the Central Virginia Regional Crash Team that are assigned to investigate a fatality or crash scene take measurements to draw a two-dimensional diagram that helps them determine the various factors that led to the incident.
But with the 3-D scanner technology, the amount of time and manpower those activities take will be dramatically reduced, according to Bennett. He said that for a typical accident investigation, six people are sent to the scene. But thanks to the efficiency of the 3-D scanners, as few as two people could probably do the same job, not counting traffic control personnel.
“What takes us hours or days to take these measurements, [the 3-D scanner] can do a 360-degree scan of a scene in six to eight minutes,” Bennett said.
In regard to accuracy, Bennett was enthusiastic over the gains 3-D technology will provide his team, saying the scanners would “allow us to take out the human error” when it came to measurements.
He explained that when surveying crash scenes, a person goes out with a tripod and laser measurer, and another person is out at the distance being measuring. Little things like the lean of the tripod can skew results by fractions of inches.
But the 3-D technology scans 360 degrees from a fixed point and everywhere the laser touches, the scanner will take 64 measurements for every one-inch-square area. Those data points are collected into what Bennett called a “cloud cluster,” which is downloaded onto a computer to reconstruct a 3-D scene.
“In a crash scene, typically we’ll measure 400 points, maybe 500 or 600 on a really big scene,” Bennett said. “[But] this one is going to give us 40 million points. To me, that’s crazy.”
With a fully functioning 3-D model, the scene can be accessed anywhere and anytime as a permanent record of an event. The 3-D imaging gives forensics teams and other officers the flexibility to change the model as needed, particularly when used as evidence in a courtroom.
In a fictional example, Bennett said if there was a murder scene and the suspect is a 6-foot-4 male and a defense attorney comes up with an unknown suspect who’s 5-foot-1. Using a 3-D model, his team can take the difference in height and prove or disprove whether a 5-foot-1 suspect could actually have committed the crime.
While items such as blood splatter evidence or the point of entry of a bullet or knife are common factors used by expert witnesses to help determine a person’s guilt or innocence, having the three-dimensional look adds clarity to the process of event reconstruction.
“You can go back and re-create scenarios and come up with a truer picture of what may have happened,” Bennett said. “This will give you a tool to prove or disprove theories.”
Creating a 3-D model is just the beginning. Bennett revealed that the Central Virginia Regional Crash Team is also looking into acquiring software that will animate the 3-D scenes. The program can take a 3-D image and manipulate the data to create a 3-D animation to show a judge or jury the investigators’ theory of what happened in an incident.
Although Bennett stressed that photos of a scene will still be taken, he believed the 3-D technology will bring a dynamic element to both investigations and courtroom proceedings.
“We can take a virtual 3-D model into a courtroom and take the judge to the scene, and virtually walk him around a scene of a car that is crashed, fly him over the scene, zoom in and back on it giving an overall picture,” Bennett said.
Discussion Starter: Is 3-D imaging for law enforcement a good investment, or should resources be allocated elsewhere?
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