The next dimension: Detectives and crime scene investigators are using 3D tech to bring crime scenes to life
By David Spraggs
Detectives and crime scene investigators are using 3D technology to bring crime scenes to life.
Since the earliest days of trial by jury, detectives have been searching for new ways to help jurors visualize crime scenes. In this pursuit, law enforcement quickly adopted photography and hand-drawn diagrams to create two-dimensional representations of crime scenes.
These basic courtroom graphics have always been, well, as the term two-dimensional indicates…flat, lacking vertical depth. But not anymore.
Using new computer and photographic technologies, investigators can create diagrams with complex 3D surfaces and immersive 360-degree images. Such high-tech representations of crime scenes allow for much more accurate presentation of bullet holes, blood spatter, and other evidence that’s hard to document with 2D methods.
Since visual documentation is considered one of the most important types of evidence presented to a jury, the details of a diagram—or lack of them—can dramatically impact a jury’s perception of the chronology and probable events surrounding the crime, which can ultimately impact the verdict.
So how do you recreate a crime scene in 3D? Well, unless you want to make a diorama, you’ll need a computer and some special software. Solutions range from about $500 to more than $60,000. How much you spend will depend on the complexity of the equipment and software that you want to acquire and the desired level of detail in the final product. The most cost-effective solution is to purchase diagramming software that accepts “Z” axis or vertical measurements.
To use these tools, CSIs or detectives at the scene use a tape measure or inexpensive laser measuring device to manually measure length, width, and height of the location and the evidence. These data points are entered into the software by hand then used to create the 3D diagram.
If you want to spend a little more money for greater precision, you might want to integrate a sophisticated measuring device such as a total station (a surveyor’s tool) to electronically capture distance information.
Using a total station, you can accurately measure distances and angles, recording 3D data. The total station is connected to a small device called a “data collector,” usually a PDA. The measurements are stored electronically on the data collector and can be automatically transferred into a 3D software program. The advantages of working with a total station and a data collector include increased automation, faster measurement, and many more measurement points, yielding a more detailed diagram.
Another option for obtaining 3D measurement is through the use of photogrammetry, the science of extrapolating 3D measurements from 2D photographs. Software advances have made this process easier, considerably less expensive, and more accurate than ever. And photogrammetry has also been merged with immersive imaging to provide a unique view of the crime scene along with precise 3D measurements.
Immersive imaging has been used in real estate sales for years, yet only recently have police departments begun to use this technology. An immersive image provides a 360-degree view of the scene that the viewer can scroll around; it’s almost like being in the crime scene. This is especially powerful when combined with 3D measurement.
The following is a collection of some of the most widely used tools for 3D diagramming:
Crime Zone from Beaverton, Ore.-based CAD Zone is one of the most popular forensic diagramming software packages on the market. CAD Zone has been developing forensic software products for more than a decade and it shows in the quality of Crime Zone.
A unique feature of Crime Zone is its ability to create a 3D model from a 2D diagram with the click of a button. The 3D model includes all the 2D measurement information and can be viewed from any perspective. Additionally, measurements can be entered in baseline or triangulation form, making it far easier to place evidence in the diagram. Small details count, like articulated joints on the figures that allow the user to ensure the body is accurately portrayed in the diagram.
Departments using a total station can purchase Crime Zone with Pocket Zone for $995. Pocket Zone is data collection software that can be loaded on the handheld computer of your choice and connected to a laser measuring device. The 3D measurement data is easily imported into Crime Zone, greatly speeding up the workflow. Also, Pocket Zone is the only data collection software specifically designed for law enforcement, not surveyors, so it’s easier to use than many of its competitors.
The DeltaSphere 3000 3D scanner and SceneVision 3D from Chapel Hill, N.C.-based 3rdTech are two of the most amazing law enforcement products that I’ve ever seen. The DeltaSphere 3000 3D scanner is a high-speed scanning laser rangefinder that’s kind of like a total station on steroids. By that I mean it’s capable of taking more than 25,000 measurements per second.
Users set up the DeltaSphere 3000, and it automatically scans the scene, taking millions of precise measurements along with digital photographs. 3rdTech’s SceneVision 3D software then combines these data points and digital photographs to create a high-resolution digital recreation of the scene. This diagram can be rotated around any axis and viewed from any desired perspective. You can zoom in or out and add closeup photos of specific evidence. In addition, extremely accurate 3D measurements are possible of any items in the scene and tools are included for bullet and blood spatter trajectory.
The effective range of this unit is about 40 feet. You really need to see the resulting diagram on a computer to fully appreciate the capabilities of the DeltaSphere 3000. The DeltaSphere 3000 creates the most accurate and detailed 3D diagram I’ve ever seen. Price is around $40,000, depending on the exact configuration.
DeChant Consulting Services of Bellevue, Wash., offers a unique photogrammetry software package called iWitness that’s designed specifically for crime scene and crash scene measurement. It’s simple to use but very powerful.
Here’s how iWitness works: Take three digital photographs of the same scene from three different angles. At the scene, measure one distance visible in all three photos. Next, import the images into iWitness and mark six corresponding points that are visible in the images. The software automatically orients the camera in 3D space and processes the data to provide accurate 3D coordinates of any points marked in the scene.
The data from iWitness can be directly imported into a variety of computer-aided drawing (CAD) systems, including Crime Zone. The bottom line: from one measurement and three photos iWitness, which retails for $895, can accurately determine 3D distances of the crime or accident scene.
The SpheroCam HDR distributed by Linear Systems of San Bernardino, Calif., is truly on the cutting edge of technology. This system combines a high-resolution (up to 50 million pixels), high-dynamic-range camera with precise 3D photogrammetry.
To use the SpheroCam HDR, you place the specially calibrated digital camera system (with a 16mm fisheye lens) atop a tripod in the center of a crime scene. The camera then rotates 360 degrees, capturing everything from the floor to the ceiling.
The resulting immersive image allows the user to pan up and down and left and right. A zoom tool allows the user to look closely at evidence in the scene. The unique feature of this system is that any item can be accurately measured in 3D space by simply dragging a slider between two points.
Multiple scenes or rooms can also be linked together by hotspots to create a “virtual reality” tour of the crime scene. The included software is intuitive and features image encryption and user verification to ensure the veracity of the images.
This advanced system is not cheap. It’s priced from $45,000 to $70,000, but you may find it worth the price, especially when you consider its flexibility.
MapScenes from Canada’s MicroSurvey is marketed as a “Complete 3D scene diagramming tool.” The software is designed for both crime scenes and crash reconstructions, and is sold in two versions, Pro and Lite.
The Pro version of MapScenes sells for $1,395 and is designed for agencies using total stations or other electronic measuring devices. MapScenes Pro is designed to be used in conjunction with MicroSurvey’s Evidence Recorder Pro ($995) to collect electronic measurement data and transfer it into your computer.
MapScenes is a powerful diagramming tool that allows for animated viewing of the diagram in 2D or 3D. The included symbol library contains more than 7,000 items, the most of any diagramming software. And digital photographs can be linked to the diagram to show specific details.
All of its features could lead you to believe that MapScenes presents users with a steep learning curve, but the included tips, manual, and training movies really help get you up to speed.
Another immersive photography system that’s being used for law enforcement applications comes from Van Nuys, Calif.-based PanoScan. The PanoScan system features a high-resolution, high-dynamic-range camera on a tripod mount that rotates 360 degrees. As the camera rotates, it captures a seamless image of an entire scene. The image can be output as a panoramic print or shown on screen.
PanoScan’s new Mark 3 camera captures images much faster than its predecessors, has increased data storage capacity, and downloads faster with USB 2.0 connectivity. PanoScan equipment is currently on duty with a number of agencies, including the San Bernardino County (Calif.) Sheriff’s Department, the Kern County (Calif.) Sheriff’s Department, and the Los Angeles County Sheriff’s Department.
Take a Test Drive
Agencies considering the purchase of 3D diagramming and imaging tools need to consider many factors, including system cost, simplicity, training issues, and support.
That’s why the old adage, “Try before you buy,” is true here. Most vendors provide a demo version of their software so you can use the product and really determine if it fits your needs.
Immersive and 3D technology will continue to evolve but it’s mature enough that most agencies can benefit. Maybe now is the time to consider adding this tool to your agency’s toolbox.
David Spraggs is an investigator and firearms instructor with the Boulder (Colo.) Police Department. He also teaches forensic photography and crime scene investigation.
|Back to previous page|