Sharpening Crash Mapping Skills with Tools and Training
Written by Bob Galvin   

Whether a truck broadsides a car at an intersection, or a drive-by shooter opens fire on a neighborhood street, both incidents represent a crime scene. Therefore, each scene’s evidence is essential and must be carefully documented and collected.

If presentation of evidence from a crime scene is required in a courtroom, today’s investigator has some of the most compelling technology at his fingertips. He’ll need it. After all, jurors, conditioned by years of television crime dramas strutting astounding forensic technological advances, have come to expect a sophisticated level of evidentiary presentation. Yet, much of the whiz-bang CSI technology that appears on TV is rarely seen or used in the real world of crime investigation. But technology is king, and many law enforcement agencies are adopting it to make the presentation of evidence as clear, detailed, and convincing as possible.

A basic checklist of crime scene documentation tools includes:

  • Photographs
  • Eyewitness testimony
  • Video footage of scene details
  • Crime scene diagram
  • Measurements of scene

Decades ago, plotting crime scene evidence points and creating a diagram was pretty basic, usually requiring a steel tape measure and paper and pencil to create a rough sketch of the scene. Fast-forward to 2013 and these manual steps have been totally automated. For good reason. There is pressure to swiftly reopen partially or fully closed roads when crashes occur, plus officer safety is paramount. Even so, the investigator must substantiate his collected evidence before scrutinizing jurors and attorneys.

As for the tools, the most basic technology is a total station with reflectorless capabilities and a data collector. The main providers of the total stations are Sokkia, Leica, Trimble, Nikon, and Nokia. Leading drawing software makers include The CAD Zone, Inc., MapScenes, and Visual Statement.

Mapping in 3D Reveals Vital Details

While many crime and crash scenes require only a 2D diagram, some are complex enough to warrant a 3D or animated presentation that can be helpful in a courtroom. These methods of scene depiction are welcome and even expected. Reconstructionists have effectively shown how 3D and animated scenes give perspectives of an incident’s sequence of events, or of a driver’s visual orientation, that help jurors understand what they are seeing.

Sgt. Tim Kravjanski of the Westbank (British Columbia) Police Department—a member of the department’s collision analysis team—investigates both crash and crime scenes. He considers 3D scenes crucial for making scene details clearer to a jury. Kravjanski uses the MapScenes Forensic CAD desktop mapping software and Evidence Recorder (EVR) evidence collection program.

It is easy to see why the sergeant prefers building scene diagrams in 3D. For example, he recalls an incident in which two males were shot on a roadway near an elevated apartment complex with a parkade. Witnesses, Kravjanski explains, were standing on a deck above the parkade and watched the shooting incident unfold. “For evidentiary purposes, we created a 3D diagram of the whole area in MapScenes (Forensic CAD), including the apartment with its decks,” Kravjanski said. “This allowed distances to be measured, and to show where witnesses were positioned and what they saw, and any obstructions in the way. The 3D diagram was perfect because you could also see where trees were and how tall they were.”

The sergeant captures scene evidence with a total station that is linked to the EVR program that displays in real-time the evidence it captures. “With EVR, it’s the ability to put a note on every (evidence) point that you take and do it quickly,” Kravjanski said. EVR not only displays the diagram, but fills it with important details such as linework and labels, all in 3D and with proper polar coordinates. “Once I take the diagram into MapScenes, the only thing I do is add trees, signage, telephone poles, and any other details,” Kravjanski said.

Animation Demonstrates What Drivers Could See

Lorne Starks, who operates California- based D&S Investigations, investigates cases ranging from single-vehicle to multi-vehicle collisions. He has given expert testimony in more than 275 court cases involving traffic accident reconstruction, accident causation, damage analysis, and collision factors. Often, Starks is called upon to investigate collisions well after they have occurred, and with little physical evidence. Starks maps scenes with a Laser Technology, Inc. (LTI) TruPulse 360 R measurement and mapping laser. He also adopted The Pocket Zone data collector from The CAD Zone, Inc., that works with the LTI laser system. The Pocket Zone works with a Pocket PC to take measurements collected by the laser system right at a crash scene in real-time. Consequently, Starks can transfer all of his evidence points from The Pocket Zone into CAD Zone’s The Crash Zone diagramming program.

Starks is a big fan of animation, and uses Crash Zone to create 3D animations. For example, Starks can import a satellite photo of a crash he has investigated directly from Google Earth. Using that photo to overlay a diagram he has created in Crash Zone, he then can animate the scene. “You can actually place the camera (for creating the animation) anywhere you want in the scene,” Starks explained. “So, for example, you can place the camera showing the driver’s perspective as it’s approaching an intersection, and this shows what the driver would actually see.”

It is typical for conflicting statements from drivers involved in an accident to arise, most often claiming something was blocking their view just before the crash occurred. “But with animations, you can show a camera in one car approaching where the collision occurred, and then you can switch the camera over to the other car and turn it as though you’re turning your head to see the approach of the vehicle,” Starks continued. “In this way, you see when the approaching vehicle is first visible and you’re able to get a distance. This will validate whether or not something was blocking the driver’s view.”

Laser Scanners Give Numerous Crash Scenarios

Laser scanning is the latest method of mapping a crime or crash scene and, although more costly than the ubiquitous total station, it gives unparalleled details of scene evidence. A laser scanner captures millions of data points and the entire scene precisely as it appeared. Also, 3D walk-throughs are possible.

Duane Redding, executive vice-president of 3Con LLC and executive director of Redding Forensics Ltd, feels laser scanning will not displace any mapping technologies, but will be a first go-to tool. “One of the advantages we’ve seen with laser scanning is a 60-70 percent reduction in time for investigators working major accident scenes when using three-dimensional laser scanners,” Redding said. He also cited vastly decreased human error because a laser scanner allows users to return to a scene any time and either validate or query any measurement that is deemed suspect.

Although many scanners have their own proprietary scanning software that collect points, register multiple scans into a single scan, colorize, and check elevations, they do not allow diagrams to be placed on top of the data. This is what a scanner’s user needs because, as Redding advises, “Once you have that data in a nice, clean point-cloud format, software from The CAD Zone, MapScenes, or Visual Statement can extract this data.”

Point Cloud Provides Valuable Evidence

Point cloud software that works with laser scanners is the latest innovation for more effective scene mapping. A new version of the MapScenes System for crash scene mapping and reconstruction, for instance, includes Evidence Recorder and Forensic CAD 2013 plus two add-on modules. The new modules include an animation module that builds compelling animated reenactments, and a point cloud module for drawing features via stationary, mobile, or airborne laser scanners. Visual Statement offers its EdgeFX Point Cloud software that is fully interactive, accurately measures distances in seconds, and uses 100 percent of the point cloud it maps. The CAD Zone, Inc. has introduced its CZ Point Cloud software. When CZ Point Cloud is used with The Crash Zone, the point cloud and Crash Zone diagram are displayed simultaneously so the investigator can work in either window. The diagram is built automatically in a second window based on the exact coordinates of the points selected from the cloud.

Customized Coding a Big Advantage

Most traffic investigators will not be using a laser scanner to map scenes because the scene may be not require it, but also due to a scanner’s cost which easily exceeds $100,000. A total station or laser mapping system is more likely to be the tool of choice. Nevertheless, a total station with built-in or separate data collector, evidence collection software, and a diagramming program are the basic components for documenting most crash and crime scenes.

Senior Trooper Christopher Ray of the Texas Highway Patrol recently completed a training class on Forensic CAD 2013, and found the software’s improved resection and diagram coding capabilities to be highly advantageous. With the resection feature, Ray noted, “If we have just a couple of evidence points (skid marks, for example) even though the entire crash scene was not marked, we can go back to the scene and create a drawing from just those two points.”

Ray also can create his own codes in Forensic CAD 2013. For instance, if he wants to notate “edge of pavement” on his diagram, the software allows him to assign the code EP1, EP2, etc. In this way, Trooper Ray explains, “You can automatically connect points that relate to a specific code. You can put a code next to a point and know exactly what that point was,” the trooper added. “You don’t have to memorize the codes.” Forensic CAD 2013 offers a library of 7,000 symbols specific to crash and crime scene diagramming, some in 3D.

Training is Key to Scene Mapping Proficiency

For any of these technologies to be useful and valuable, investigators who plan to use them, or who may need to brush up on newly introduced software versions, must have adequate training. Most accident investigation and forensic mapping courses cover basic steps in at least 40 hours. According to Mike Selves, a certified crash reconstruction specialist and trainer in South Dakota, “We want students to be confident that when they leave the class, no matter what scene they’re on, they can shoot it (using a total station, typically), move around within it (aided by evidence recorder software), download it into a drawing program, make a drawing, and present that in court.” Selves usually conducts two-week courses to cover the entire scope of his instruction.

Joel Salinas, a veteran crime scene investigator and trained reconstructionist with the Vallejo (California) Police Department, heartily agrees with Selves. Salinas, who teaches MapScenes and CAD Zone classes, worries that too many investigators rely too much on their equipment vendor to teach them scene mapping and diagramming basics. Salinas recommends two weeks for his students, with one week devoted to mapping a scene with a total station, and a second week on learning how to diagram a crash scene. After all, Salinas warns, “If the operator is not able to answer questions about how he used his equipment and evidence collection software, he may not get his diagram into court.”

Salinas has students learn how a total station operates to the point where they can go out and map a scene and produce a drawing on their own. They are taught how to set up a total station and map a crash or crime scene. Students learn how to draw basic linework, how to use basic features of evidence collection and drawing software for editing their scene, and how to print it.

In addition, students are given both a written exam and assigned a final project in which they must demonstrate proficiency.

Evidence is Main Focus

Much of the crash investigation course Salinas offers focuses on types and scope of evidence. Specifically, in a crash scene, as evidence leads up to the heart of the scene, “there would be a nice set of skid marks,” Salinas said. Students in his course also need to learn if the driver involved in a crash reacted, and look for crash data and post-crash data: when the vehicles came to rest, where the debris field lies, and any tire marks.

Real Crash Taps Students’ Skills

Getting adequate training is what Selves considers the biggest challenge in crash scene mapping. This is why he and Salinas—who has partnered with Selves’ firm—Collision Forensic Solutions, learn how to use a total station and mapping and diagramming software before heading into the field.

In August, nine students in a class Selves was teaching in Amarillo, Texas, got a hands-on experience to test their newly acquired crash investigation skills. On the last day of a two-week class, Selves received a call just after his class began about a nearby fatal accident that occurred on a five-lane road and involved a car that had been t-boned by a truck at an intersection. Immediately, Selves stopped his instruction. “I took the class to the scene, but didn’t monitor the students, didn’t do anything with them,” Selves said. Instead, he instructed the students to map the crash scene on their own using the training they had just received in class. “I had confidence in their abilities,” Selves said, “and they mapped the scene perfectly.” Students arrived at the scene at 9 a.m. and were back in Selves’ class before noon. “They were very proficient,” Selves said.

About the Author

This e-mail address is being protected from spam bots, you need JavaScript enabled to view it is a freelance writer who covers topics related to law enforcement and the technology of crime scene and crash scene reconstruction. His office is located in Oregon City, Ore.

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