Like many other businesses around the globe, public safety agencies are sending workers home, meeting virtually, and observing social distancing on the job. For those of us in crime scene units and crash reconstruction, it’s not that easy.
Our jobsite—whether at the scene of a violent crime or fatal collision—was full of unknowns before the COVID-19 pandemic. We’ve got good reason to be even more anxious about the duration and the closeness of our interactions during our investigations in the current environment. We’re concerned about how we’re going to keep ourselves, our families and our communities safe and keep faith with our mission to produce forensically sound investigations.
An investigative environment with widespread infectious disease is a significant distraction. It’s good to remember that live subjects who are actively expelling the virus in an uncontrolled environment are the most serious threat. However, COVID-19 remains present for extended periods of time on hard surfaces where an infected person has been present. It’s essential to be cautious and keep a PPE barrier in place, even with the deceased.
Obviously, we won’t stop investigating major crimes and crashes, but there are sensible steps we can take to reduce our personal risk factors. Prior to this pandemic, the benefit of on-scene efficiency was measured in terms of productivity. Today, time of operation and therefore duration of exposure has grown as a concern. Every minute we spend on the scene is another minute where we might rub our face the wrong way, our PPE could fail, or we could encounter some other element that’s out of our control.
However, we can control the speed with which we work by optimizing our standard operating procedures (SOP)—specifically through our laser scanner’s settings and our scanning routines—so that we can quickly get an accurate forensic map and get out of harm’s way.
1. Skip the leveling process
Many survey grade laser scanners can be precisely leveled. This is not always necessary and can be a good point of compromise when time of exposure is a concern. Unless you’ve been trained to level your scanner in under a minute, turn off the dual-access compensator and scan unleveled. If an operator is spending five to 10 minutes per setup, it’s not too long before they’ve added an hour on scene. In that case, especially in indoor environments, it’s better to scan unleveled in order to speed up your capture and decrease your time on scene. If you don’t have a self-leveling instrument, it may be more difficult to post-process your data, but the extra amount of work will be spent in a safer and more controlled office environment. And by the way, get in touch with me if you want to become more proficient at leveling your scanner.
2. Reduce your scan density
While higher density point clouds have better detail, they also take much longer to scan. Reduce your scanner’s point spacing to only what’s necessary to capture what you need. Instead of using your standard setting, evaluate each scene to determine the lowest density you can get by with. A low scan resolution of a close-proximity wall, for example, is often enough. Remember that critical measurement items like blood pattern require tight point spacing—no matter what.
3. Turn off the imaging function
If it adds significant amounts of time, don’t take photographs with your scanner’s internal camera system. Instead of photo-realistic colors, your scan environment will only have intensity colors, black and white values, or a rainbow-like hue. But I think it’ll be pretty easy to explain to a jury that we don’t have RGB colors because we were trying to protect the safety of our crime scene investigators by reducing their time on scene during the COVID-19 pandemic.
4. Disinfect your equipment
Your equipment has been exposed to the same environmental risks you have. It’s important to follow the same cleaning protocols for your equipment as you do for your vehicles and your office spaces. Your scanner is durable equipment that’s going to be used by several people, so make sure it’s clean when you put it back in the box. That includes the tripod and any of the accessories that were exposed in that environment. We’re able to use 70 percent alcohol to wipe down our Leica Geosystems equipment. If you’re not sure what you can use to disinfect your equipment, contact the manufacturer for instructions.
Finding a balance between documentation quality and personal risk
All things being equal, dense point clouds, leveled instruments and photo-realistic imaging are fundamental to a high-quality documentation process. But we’re not in an all-things-equal environment right now. We’re in a risky environment, and there is a huge potential downside for people who must spend significant amounts of time in an infectious area.
Do what you must to continue to get comprehensive scene capture but reduce your footprint and your time on scene as much as possible by making some of these reasonable compromises during the COVID-19 pandemic. We’ll get through this, and it will be much more manageable for everybody if we take these simple precautions.
About the Author
William Henningsen is the manager/director of the Omaha Police Department’s Forensic Investigations Unit. Henningsen, who has been forensic mapping for more than 20 years, led the agency’s progression from tape measure to total station to 3D laser scanner, making it the first police department in the state to implement laser scanning technology. In addition to supervising the agency’s team of certified crime scene investigators and forensic analysts, he has been involved in training and consulting with Collision Forensic Solutions since 2015. To-date, Henningsen has captured and processed 3D laser scan data on more than 300 major crime scenes. He can be reached at Will@CollisionFS.com.