A large percentage of crime scenes occur at night or in dark locations. Oftentimes, suicides and overdoses take place in covert and low-light locations like garages so as not to draw attention. The same goes for homicides in drug houses, condemned or boarded-up homes with no power, or indoor arson scenes where power in the building has been knocked out. Crime scenes need to be documented to provide critical information about the crime scene.
Documenting these scenes provides valuable information. A picture may be worth a thousand words, but crime scene mapping using 3-D laser scanners provides context, accuracy, and speed. These scanners create 3D models of the crime scene that the investigators, judge, and jury can look at months after a crime has taken place and the scene has been cleaned.
Lighting is everything in photography, so low light scenes are extremely difficult to photograph let alone scan with a laser scanner. Low lighting can result in a loss of detail, grainy images with signal noise, and reduced dynamic range to the final output.
We were curious if lighting could benefit a geo laser scanner in the same way lighting benefits a camera for photography. Last week, FoxFury Lighting Solutions and Airborne Works tested out a proof of concept lighting solution to use in conjunction with a 3D laser scanner. In this case, a Leica BLK360 laser scanner was used to scan or map a mock homicide in a hotel room.
Our mock crime scene consisted of a single victim in a hotel room with a single murder weapon on a table. The location of the victim relative to the gun makes it clear that this is a case of foul play and not a suicide. All lights in the room were turned off except for one table lamp near the curtained window.
Proof of Concept Lighting
The proof of concept lighting consisted of multiple battery-powered FoxFury Rugo lights mounted in a 360-degree array underneath the Leica BLK360. The lights being mounted to the laser scanner provided even fill lighting with minimal dark spots for the scene. The ability to have lighting in all directions allowed images to be overlayed with greater consistency between each image. The small lightweight Rugo lights mounted directly to the scanner rig provided a simple, portable lighting solution that moved with the scanner to multiple locations around the scene.
Marc Langley from Airborne Works took 5 scans at different locations in the room. Each scan captures up to 360,000 individual measurements per second as it rotates 360 degrees for 3 minutes. The scanner took full-color panoramic images overlaid on a high-accuracy point cloud.
In the end, we were pleased with the results and felt that the lights improved the overall output of the Leica scanner. The model has much better detail than if only the single light in the room were used. The lights mounted on the scanner provided a consistent, even fill lighting that reduced dark shadows in the scene. This proof of concept was successful and we’re excited to continue testing this idea on different scenarios.