Pictures still may be worth a thousand words, but when they involve showing details of a crash scene in a courtroom, jurors may not always get the full picture of how a crash occurred and who was at fault. Receiving too much information might actually hamper a juror’s understanding of a crash’s fluidity, as the juror succumbs to visual and information overload.
The good news: Today’s crash scene documenting technology enables investigators to recreate and document crash scenes with optimal accuracy, clarity and details. The result: more compelling and credible courtroom presentations of crash cases.
Data Collection
For more than 30 years, the standard tool for crash scene reconstruction has been the Total Station. It’s easy to operate, gives precise measurements, shoots short and long distances, and can even capture evidence data points without forcing its operator to work directly on a roadway. Keeping yourself safe while mapping a crash scene and mapping quickly enough so that partially closed roads can be reopened, are always challenges.
This is why Kevin Bryce, a partner and trained crash reconstructionist with Bryce, Williams & Associates Traffic Accident Reconstruction & Analysis in Kildare, Texas, acquired a Topcon GPT-300SLW wireless and prismless total station when he opened his private practice. One of the total station’s main draws is “the ability to take measurements in the roadway without getting directly in the roadway,” says Bryce, a former Texas state trooper.
Bryce recalls one 1,500-foot-long crash scene involving an 18-wheel truck and a passenger car. The car ended up under the truck’s trailer and was then dragged several yards to its final resting place. The crash occurred on an overpass of a multi-lane highway.
“You could not see from one end [of the scene] to the other,” says Bryce. This is where the total station proved essential to measuring the complex scene. “The ability to set up the instrument and take measurements, then move it to a new location and continue those measurements without having to get directly in the roadway were all critical to being able to retrieve the evidence.”
The total station’s huge display on both sides yielded more convenient read-outs in the field, along with the ability to shoot fast-distance measurements of up to 10,000 feet. Other key features are an onboard data collector that stores up to 24,000 points and the ability to view measurements on a display right after they’re taken, preventing any missed points.
Satellite Photos & Software
Joel Salinas is a veteran crash and crime scene investigator with Vallejo, Calif., Police Department who teaches accident investigation courses and forensic mapping. For his own crash cases and classes he teaches, Salinas uses MapScenes Forensic CAD and Evidence Recorder. One of the key features in Forensic CAD he finds valuable is the ability to build a library of feature codes. When mapping a crash scene, the reconstructionist will need code roadway features, such as edge-of-pavement, top-of-curb, lane lines, double yellow lines, solid white lines, limit lines, etc.
“You can build a library of these feature codes based on abbreviations,” Salinas says.
MapScenes Evidence Recorder protects all data recorded. The software also offers 3-D modeling to enable the user to rotate the scene around on the data collector’s computer screen, thus ensuring all critical evidence data has been collected.
Animation Shows Drivers’ Perspectives
Lorne Starks, a trained reconstructionist and fraud examiner with California-based D&S Investigations, has given expert testimony in more than 275 court cases involving traffic accident reconstruction, accident causation, damage analysis and collision factors.
Starks maps his crash scenes using an LTI TruPulse 360R measurement and mapping laser. He also deploys a Trimble Recon Data Collector that works with the LTI TruPulse laser system. He prefers The Pocket Zone, a CAD Zone product that works with laptops and notebooks to take measurements collected by the laser system right at the crash scene—in real time. Starks imports evidence points from The Pocket Zone into The Crash Zone drawing software.
Animating scenes to create 3-D animations is a growing trend. For example, Starks can legally import a satellite photo from Google Earth into Crash Zone. Using that photo to overlay a diagram he’s created in his diagram, he can then animate the scene.
“You can actually place the camera anywhere you want in the scene [when creating an animation],” Starks says. So, for example, “you can place the camera showing the driver’s perspective approaching an intersection, and this shows what the driver would actually see.”
Let There Be Light
Many crashes occur in the evening, which means 3-D diagrams and animations need to show realistic nighttime conditions. That’s what Joey Stidham, owner of Stidham Reconstruction and Investigation LLC in Woooten, Ky., concluded: He uses Visual Statement Inc.’s EdgeFX software for this reason.
In 2011, Stidham investigated and diagrammed a crash scene involving a vehicle and an agricultural machine that was being pulled down a roadway at night (the crash killed three of Stidham’s clients). He couldn’t find this exact piece of equipment, so Stidham and his team, along with Visual Statement, built their own model of the “hay buster.” Then the team created a 3-D animation of what happened. One particular capability in EdgeFX that proved critical for the scene’s reconstruction is called dynamic lighting, which shows directional lighting, such as headlights, in a night crash.
Once the animation was created, including dynamic lighting, testing began to determine the driver’s point of perception. Stidham created a forensic map of the scene along with a custom model of the hay buster. “After we received the model, we created a 3-D animation to be used at the crash case’s mediation,” Stidham says. “This animation accurately depicted all of our findings.”
Laser Scanning: The Next Wave
No matter where you turn, the use of laser scanning for both crash and crime scene reconstruction is expanding rapidly. It has major advantages that can make its relatively high cost worth it: Its complete scene capture capability, with millions of data points, capture the scene exactly as it appeared. You can also do 3-D walk-throughs and return to the scanned data at a later date should a case and its evidence be reexamined. The result: huge time savings.
In addition to a reduction of scene investigation time by nearly 70%, laser scanning also decreases the amount of human error—measurements that may have been missed or taken improperly, says Duane Redding, executive vice president of 3Con LLC and Redding Forensics Ltd., which provides nationwide multi-dimensional laser scanning services.
“This allows us to go back and either validate or query any measurement we believe is suspect,” Redding says. “It also gives us the ability to work many different scenarios, obviously post-crash.”
Laser scanning produces a 3-D model of a crash scene, showing the complete scene exactly as it looked once a collision occurred and vehicles came to rest. Point cloud software is used in conjunction with the 3-D laser. Specifically, the scanner measures a large number of points on the surface of the crash scene, then outputs a point cloud as a data file. The point cloud represents the set of points that the scanner has measured. Two of the leading laser scanner brands used are the Leica Scan Station C-10 and FARO Focus3D.
More Evidence Captured
“We are capturing more evidence because scanners can take a snapshot of everything they see from one position,” says Bobby Jones, owner of Bobby Jones Accident Reconstruction and Investigation Services Inc., Knoxville, Tenn. How is this accomplished? By applying scanner and point-cloud technology.
Jones discovered how powerful and thorough this technology was when using The CAD Zone Inc.’s CZ Point Cloud program. For one crash case, he used a scanner to map a single-vehicle crash in which the driver was ejected due to high speed. The scanned scene showed not only the body’s trajectory through a series of trees, but plotted points in the trees along its path: “We didn’t realize the information was there, but the scanner saw it. The software easily extracted this evidence from the scene.”
The point-cloud diagramming software Jones uses makes it fast and easy to accurately identify the correct points. It allows a diagram and point cloud to be displayed simultaneously so that the investigator can work in either window. Animated fly-through of a scene is also possible: “This allows jurors to visit the scene and view evidence from virtually any angle, showing witness points of view, bullet trajectories and other critical evidence.”
Unlike other technologies, laser scanning is accurate and reliable for documenting both the roadway and the surrounding environment—and it’s fast. A typical scan can take six to seven minutes followed by the time to capture the image. The laser scanner excels in documenting damaged and exemplar vehicles, Salinas added.
“The vehicle can be scanned, and instead of obtaining one set of measurements for the damage profile, multiple measurements can be made as needed back in the office,” says Salinas. Also, “interior scans of vehicles can aid in determining how occupants were injured and for determining driver and passenger positions.
“One of the big separations with laser scanning is millions of measurements taken at the scene. We have the actual measurement data,” says Redding of 3Con. “That’s as close to irrefutable evidence as you’re going to get.”
Redding makes it clear to judge and jury what they are about to see via the scanned crash scene—that it is not an animation or recreation of the scene. “I can take jury members and put them at the vantage point of a witness, driver, victim or basically anywhere in that scene. … I have the scene right there, and that’s a key point to admissibility. There’s no interpretation needed for this data.”
Conclusion
However you choose to document the details of a scene, accident evidence needs to be collected diligently in order to tell the story of what has happened. It also needs to be done with utmost attention to the safety of the officers collecting the evidence. Finally, it needs, in some instances, to stand on its own in court. Thankfully, technology has come a long way in helping us do that.