That’s How We Roll: Testing Object Distances When Thrown From Vehicles
Every case presents unique challenges. Accidents often result in limited or conflicting evidence, making it vital to uncover the truth. Whether a case involves a transportation collision, slip or fall accident, product malfunction, biomedical analysis, equipment failure, or even a crime, understanding what happened and why it happened can significantly influence the resolution of legal disputes or insurance claims.
Sometimes, you need the expertise of a forensic engineer for a unique case. Discover how one of our biomechanical engineers presented findings clarifying the facts in an exceptional situation.
That’s Not My Evidence:
The expression “possession is nine-tenths of the law” has become a familiar adage in the public’s understanding of various legal issues. Whether someone has, or had possession of, an item that serves as evidence of a crime, and how they tried to dispose of that item, are burdens the criminal justice system must prove. This could involve anything from illegal drugs to a suspected murder weapon, or even something as minor as littering. In courtrooms across the United States, these questions are often evaluated and presented as either direct or indirect evidence.
Ultimately, it comes down to a simple scenario: how can it be proven that the evidence found near a suspect’s vehicle is related to the suspect? Conversely, can it be shown that factors such as proximity, conditions, and physics prove that recovered evidence could not possibly be linked to the suspect in a criminal case? Quality Forensic Engineering plays a crucial role in addressing these types of questions. Here is one such story.
Facts of the Case:
This case began with a high-speed chase along Interstate Highway 95 in Florida. The suspect’s vehicle fled from a traffic stop and was pursued on suspicion of possessing a large quantity of drugs, in addition to fleeing arrest. The chase ended when the vehicle collided with another car on the roadway and became disabled.
During a law enforcement search of the suspect’s vehicle, no evidence was recovered. However, approximately half a mile north of the crash site, a drug package was discovered approximately 45 feet from the edge of the roadway. The arresting officer suspected the drug package had been thrown from the vehicle during the chase.
The defense retained an expert, a former police officer, who argued it was physically impossible for the package to have been thrown that distance. This raised reasonable doubt regarding the connection between the package and the suspect. Additionally, there were no witnesses to confirm that the package was thrown from the vehicle.
What Qforensics Did:
Qforensics was retained to answer two specific biomechanical questions: How far can a drug package realistically be thrown from a moving vehicle, and do those distances align with the measurements taken at the incident location? To achieve this, we utilized two key processes:
- The first process involved examining the physics of the throw. We considered factors such as trajectory, wind resistance, vehicle velocity, and the likelihood of a package tumbling upon impact. While these questions were analyzed mathematically, we also conducted on-site testing by throwing objects similar in size, shape, and composition to the subject evidence.
Our engineers follow a simple philosophy for tests like these: replicate the circumstances and reproduce the results. In other words, our goals were to:
- simulate the situation to determine what an average person could achieve when throwing a comparable object from a moving vehicle; and
- adjust the variables to see if they could explain the measured distances.
The calculations are straightforward, but the testing was done with specific attention to using an analogue as similar as possible to the collected evidence in as many ways as possible.
2. In this specific case, we used a segment of a wooden 2×4 as the thrown object, since its shape, weight, and bounce (off the ground) closely resembled that of a drug package. Initially, these objects were thrown from a stationary vehicle, then at varying speeds, to analyze how far they traveled based on the vehicle’s speed. Subsequently, we utilized mathematical and statistical techniques to assess the effects of larger throwers, taller vehicles, and faster travel speeds.
Ultimately, our inquiry was straightforward: given the circumstances of the incident, do the calculated distances align with the travel distance of the drug packages recovered from the field location where the arrest occurred?
Figure 1: Diagram showing the velocity vectors of an object thrown from a vehicle
What We Found:
The package recovered from the incident site was located approximately 45 feet from the edge of the roadway. Our stationary testing yielded throw distances of up to 30 feet from a stationary vehicle. In contrast, tests conducted with the vehicle in motion (traveling at up to 40 mph) showed throw distances exceeding 48 feet, with the maximum measured at approximately 72 feet from the edge of the roadway.
The opposing expert stated that, based on their testing, the maximum throw distance was no greater than 30 feet. However, the testing conducted by Qforensics’ engineers demonstrated this distance accounted only for the airborne phase of the thrown object. In fact, video evidence from our tests showed that while the initial throw distance was accurate, the vehicle’s forward motion after the objects were thrown created a tumbling effect not accounted for in the other experts’ testing.
This tumbling effect significantly increased the distance the object traveled in our experiments, producing results that better reflected its size, shape, and internal properties. Since every test Qforensics conducted showed travel distances consistently greater than that of the recovered evidence, our findings support the conclusion that the distance the defendant would have needed to throw the drug package was not only reasonable but also likely, given the reported travel speeds.
Figure 2: Testing results from vehicle thrown objects when a) stationary, and b) in motion over 40 mph
How It Helped the Case:
Our testing served as a rebuttal to the opposing expert’s findings. We exposed deficiencies in their study design, which artificially limited the travel distance of the thrown object.
The study conducted by Qforensics’ engineers clearly demonstrated that when accounting for the defendant’s subject-specific parameters such as his height, the speed of his vehicle, and the composition of the drug package, throwing the object would have been easier than the opposing expert suggested. Therefore, our conservative estimates still indicated a strong probability the drug package could have been thrown from the defendant’s vehicle.
It is important to note the defendant’s expert did not consider the possibility of the drug package rolling after it hit the ground. This oversight meant the actual travel distance observed in real life was significantly greater. Our thorough testing, along with deposition testimony and trial preparation, helped secure the jury’s conviction and reinforced the evidence’s reliability.
Conclusion:
Forensic engineering requires a unique blend of scientific discipline, investigative skill, and real-world expertise. Unraveling the complexities of an incident can be challenging, but that’s where experienced forensic engineers make a critical difference. We go beyond simply collecting evidence; we uncover the essential facts that can significantly impact a case. As impartial third parties frequently retained by attorneys, insurance companies, and other stakeholders in litigation, forensic engineers provide an objective, science-based analysis. Trusting our expertise can be a pivotal factor in achieving justice and clarity in your case.
About Qforensics
Quality Forensic Engineering, LLC is a full-service forensic engineering firm providing engineering support to clients in accident reconstruction, biomechanics, fire investigations, patent litigation analysis, premises liability, product liability, and tire failure analysis. We use the latest technology and industry-proven techniques to provide thorough analysis, expert testimony, and conclusions for the most difficult engineering questions. Our forensic engineers support clients throughout the U.S. View our locations
