Turn Your Measurements Into Diagrams

Sometimes a quick sketch on the back of a napkin is good enough, but that’s just not going to work if you are investigating a crash or crime scene. When you’re preparing a case, especially one that may end up being presented in court, you need diagrams and animations that depict an accurate representation of the scene.  You may spend a great deal of time at the scene taking measurements and documenting every detail. What is the best way to turn those measurements into accurate diagrams?

The Crash Zone and The Crime Zone have more ways than any other program to accurately turn your measurements into 2D diagrams, 3D models, and animations. Whether you are taking measurements manually with a tape measure, shooting points with a total station, or using a 3D laser scanner, you can create courtroom-ready case materials that you know are completely accurate.

Summit County Sheriff Deputies map a crash scene with their total station.

Measurements From Laser and GPS Devices

Many crash and crime scene investigators now have access to a total station or other laser measurement devices, like those available from Laser Technology, Inc. These devices normally take special training to learn to use, but they allow you to collect measurements of a scene much faster and more accurately than you can with manual methods. While collecting and recording accurate measurements is critical, you still need an easy way to turn those measurements into a 2D or 3D diagram and maybe even into a 3D animation.

The Crash Zone and The Crime Zone can import the data from nearly all laser measurement devices, automatically turning your measurements into a diagram of points, lines and curves.  The 3 dimensional aspect of the measurements is always maintained, so you can create 2D line diagrams and an accurate 3D model of the scene, including ditches, hills, 3D curves, and so on. There are different tools available to help you bring your data into the diagram program, depending on which laser device you use and which data collection software.

Generally, manufacturers of laser measuring devices each have their own proprietary data format for their output. The measurements from some laser devices can be read from this native data format, including Laser Technology’s .raw files, Sokkia’s SDR format, and Nikon AIMS.  For other devices, you can still easily bring your laser measurements into the Crash Zone using the Coordinate Data Table. If you use your device to save your measurement data as a plain text file with a file format of .txt, .csv, .dat, or .asc, the measurements can be opened in the Coordinate Data Table. You can select from a variety of data formats so you can match the method used by your data collection device.

Deputy Bobby Jones, Knox County Sheriff’s Department, commented on the ease of bringing his scene measurement data into Crime Zone, “We have used The Crime Zone in conjunction with a Laser Technology Impulse Laser measurement system and a Sokkia total station. It imports the data flawlessly so I can quickly create finished, courtroom-quality drawings. It’s not unusual for the diagrams to be so definitive, illustrating all the evidence, that the defendant will plead guilty without contest!”

3D Laser Scanners, the Next Big Thing

Originally, investigators measured crash and crime scenes with a tape measure, then laser measurement devices, like total stations, became popular. What is the next big thing in forensic scene mapping? We predict it will be the 3D laser scanner. These devices capture an accurate, 360-degree model of a crash or crime scene, including millions of X,Y,Z data points and even color photographs. When a laser scanner is used at a scene, the resulting “point cloud” of data is an exact 3D model of the scene, frozen at that moment in time. An investigator can look at the point cloud and obtain exact measurements of anything the laser was able to hit, even years after the incident occurred!

The benefit to investigators of using a laser scanner is that they can make observations and take measurements from the point cloud, long after leaving the scene. The data is complete and accurate. The downside to using a laser scanner, is that the point cloud is huge, containing millions of points. The data file is much too large to bring into a typical diagramming program and do anything with it. Now there is a new way to create accurate 2D diagrams, 3D diagrams, and even animations from all that data.

With CZ Point Cloud, the Crash Zone screen and the Point Cloud are displayed at the same time 
so you can use the point cloud to create your diagrams.


With our new CZ Point Cloud™ software, you can easily use those massive point cloud datasets to create court-room ready diagrams and animations right in The Crash Zone or Crime Zone. This new module lets you open the point cloud in a separate window and choose just the points you need to create your diagrams. We’ve developed special tools that make it easy to select just the critical points you want from the cloud and draw lines, arcs, and curves between the points. Everything you do in the point cloud is drawn automatically in your Crash Zone diagram.

Collect Your Data With Pocket Zone™

Pocket Zone is a data collection software program for handheld computers that was developed by CAD Zone specifically for taking measurements at crash and crime scenes. It is not for surveyors. Pocket Zone is compatible with hundreds of laser measurement devices, including those from Laser Technology, Leica, Sokkia, Topcon, and Nikon. When connected to a total station or other laser measurement device, Pocket Zone records the measurement data for each point you shoot and creates the diagram as you go. You can instantly see if a significant data point is missing or was shot incorrectly. Since you see the drawing as it is being created, you leave the scene confident that all the details have been accurately measured and recorded.

The diagrams you create in Pocket Zone can be uploaded to your desktop computer and opened with The Crash Zone and The Crime Zone. There, you will see all the exact points you shot with your laser including any lines, curves, and symbols that you added at the scene.  Once in the diagram program, you can use the standard drawing tools to edit and delete objects, add more symbols, and place additional text and dimensions. The data points themselves are stored on a protected layer so they cannot be changed.

Pocket Zone user, Deputy Mark Kimsey, Hamilton County Sheriff’s department, comments on the program’s efficiency, “With Pocket Zone, we can diagram a crash right at the scene. We shoot our points from a total station using Pocket Zone as the data collector. Then we bring the data straight into The Crash Zone. There are no conversions and no chance for errors!”

A Crash Zone diagram created by Deputy Mark Kimsey, using measurement data recorded with Pocket Zone.
The inset shows a screen shot of the Pocket Zone data that was collected at the scene.

Using Pocket Zone is a great way to get perfectly accurate measurement data into the diagram program. Your data will also be completely verifiable and protected. For nearly ten years, diagrams created with data recorded in Pocket Zone have been accepted in court cases. To learn more about how Pocket Zone can make it easier to get results from your laser, visit The CAD Zone’s website at:  www.cadzone.com

Manual Measurements

If you take measurements at a scene manually, with a tape measure or similar tool, there are some special features in The Crime Zone (and Crash Zone) that help you turn those measurements into an accurate diagram.  These tools let you enter the measurements on the keyboard in a convenient format and the program places points, draws lines, or draws curves between the points.

Easy Lines

One way to draw from manual measurements is to use Easy Lines. Think of this feature like pacing off the outside of a building. First place a starting point at one corner, click your mouse to show the direction of the next corner, enter the desired distance and just click to place a line between the two points. Continue from this new starting point to select the direction and distance to the next point.  Easy Lines also has specific modes for drawing if you use the baseline or triangulation methods of taking measurements.

Easy Lines is ideal if you do not have a very large number of points to enter, because there is no way to import or preview the measurements. If you want a more powerful method of entering manual measurements, try the Coordinate Data Table.

Coordinate Data Table

When you have a large number of points, the Coordinate Data Table is the best way to turn your manual measurements into an accurate diagram.  This feature has a spreadsheet-like table where you enter your measurements.  You can choose to just place points or enter special codes that instruct the program to connect the data points with lines and curves. As you enter measurements, a preview of the diagram is displayed in a window below the table. This allows you to make sure all your points are correct before you commit to placing them in the diagram.

Depending on how you obtained your measurements, you can enter data in the Coordinate Data Table in a number of different formats, including baseline, triangulation, X Y Z coordinates, multiple laser device formats (i.e. Pt#, North, East, Elev, etc.) and GPS formats. You can even enter your point coordinates in another program, such as a spreadsheet, and import them into the Coordinate Data Table.

Use the Best Method For the Scene

When investigating a crash or crime scene, there are many choices of how best to obtain measurements. The investigator may decide manual measurements are enough, or they may prefer to use a total station or Laser Technology laser measurement system. Investigators who are lucky enough to have access to a 3D laser scanner, may prefer to use it to capture a complete scan of the scene. Maybe some combination of all three measurement methods will be most effective. Whichever method you choose, you can have complete confidence that Crash Zone and Crime Zone will allow you to use those measurements to create accurate 2D and 3D diagrams with ease.

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