What should a modern case investigation look like? Knott Laboratory offers important clues

For decades, crime and crash scene investigations have relied on photos and basic measurements to tell the story of what happened on the scene. This approach has limited investigators and juries to a two-dimensional perspective. Even the more recent addition of video evidence doesn’t offer a true picture of what occurred.

But now, laser scanning, photogrammetry, and point cloud technology allow for 3D virtual reconstructions of crime scenes. Within virtual environments, forensics professionals can view the scene from nearly any perspective to corroborate witness statements and inform investigations, and juries can view the crime scene free from biases that photo and video can inadvertently introduce.

Knott Laboratory, LLC provides forensic engineering and animation services to reconstruct crimes. Through a process Knott Laboratory has trademarked as Digital Media Forensics™, the company’s adept team comprising engineers, visualization specialists and law enforcement experts uses scientifically accurate methods and laser scan data to virtually recreate incidents as compelling, immersive visualizations.

Here’s what a modern investigation looks like, step by step.

1. INITIAL CONSULTATION AND DATA COLLECTION

2. DATA COMPILATION AND ENRICHMENT

After gathering the data from the client, Knott Laboratory must assemble the disparate evidence sources into a single virtual crime recreation. The company’s team of experts organizes and reviews the data and then works to identify what gaps in the data will need to be remediated.

“We see it as a puzzle, and we look for where the missing pieces are that we may need to gather ourselves,” explains Taylor D. Spiegelberg, senior visualization expert for Knott Laboratory. “We might need to go out to the scene and collect a laser scan. Or we may take video or photographs with a drone to give us an overhead view.”

“The Leica laser scanners are a huge advantage. We're seeing an astronomical increase ion the speed it takes to capture these scans. It gives us more points to work with, and that's better for our visualisation since we have the clarity we need." - Taylor Spiegelberg, Knott Laboratory

3. POINT CLOUD PROCESSING

After Knott Laboratory conducts any additional data capture, the point clouds from the laser scans are processed in the office. The data is registered together to ensure accuracy and alignment.

The integrity of the laser scan data is critical to the integrity of the virtual reconstruction. The constellation of data points captured by the laser scanner must be precise and accurate in order to ensure defensibility, and the data points — each bearing a precise XYZ coordinate — form the bedrock of the virtual environment. Knott Laboratory relies on the Leica RTC360 laser scanner, which can measure up to two million points per second with millimeter-level accuracy.
“The Leica scanners are a huge advantage,” says Spiegelberg. “We’re seeing an astronomical increase in the speed it takes to capture these scans. It gives us more points to work with, and that’s better for our visualizations since we have the clarity we need. We can zoom into fine details to even see cracks in structures.”

4. PHOTOGRAMMETRY AND CAMERA ALIGNMENT TO THE 3D ENVIRONMENT

Next, videos and photos are aligned with the point cloud. Knott’s software identifies features in the frames that match those in the point cloud, such as a street pole top. By triangulating the points across frames and time, the camera’s perspective is placed within the 3D environment. Distortions introduced by the camera lenses are corrected to ensure the fidelity of the imagery.

After each pertinent video or photograph passes through this process, Knott Laboratory has a three-dimensional panorama of the crime scene. This vantage point permits a multifaceted view of the scene from nearly any angle, including the perspective of any photo or video included in the evidence.

Analysis performed by Knott Laboratory using video, a high-definition 3D laser scan and matchmoving techniques made it possible to analyze sprint car movements in a fatal racing incident.

5. THREE-DIMENSIONAL MODEL GENERATION AND COLLABORATIVE ENDEAVORS

Next, the team creates 3D digital models for entities such as vehicles or individuals. Working in close collaboration with engineers, visualization experts pay close attention to data fidelity, thereby fostering the calculation of speeds, distances, and other quantifiable parameters specific to the case.

At the end of the workflow, Knott Laboratory has a virtual recreation of the event derived from laser scans and provided evidence. Investigators and juries can view the environment from the perspective of a parking lot surveillance camera, or watch events unfold from the perspective of a witness to corroborate their statements.

“We can rotate the perspective to the side or to the top, and that changes everything,” says Stanley C. Stoll, CEO and principal engineer for Knott Laboratory. “You can identify objects that blocked critical elements of the situation. You can tell the motion of a vehicle or a person. You’re taking out the ability for opinions and bias, and you’re left with a reconstruction of the true incidence. And the technology is here and available for us to use.”

EFFECTS OF 3D CRIME SCENE RECONSTRUCTION ON JUSTICE SYSTEM

The resulting 3D reconstructions provide crucial value to the justice system by giving an objective view of the scenes. Complex scenes involving multiple shooters from multiple angles can be intuitively understood, and juries — incorrectly conditioned to believe that video provides an unbiased perspective — can see events from an objective angle.

Jacob E. Martinez, a criminal defense lawyer who has worked with Knott Laboratory, has experienced the impact of this modern investigation process firsthand. “If applied widely to the criminal court system, [the laser scanning] technology can be a game changer,” he says. “You can reconstruct a scene months or years after an incident occurred, and you can revisit it from as many different perspectives as possible. You can minimize, if not remove, the doubt of how an event unfolded.

“It’s worth its weight in gold when you’re dealing with especially serious criminal allegations where people’s reputations and liberty are at stake,” he adds. “And you can determine the outcome not by approximations or best guesses, but by indisputable science. That’s huge.”