Biomechanics Expert Witness is Qualified to Opine on What Caused Plaintiff’s Injury 

This matter involves an incident that occurred on May 29, 2020. At the time, the Plaintiff, David Zuniga, was present during the George Floyd protests in Grand Park, Downtown Los Angeles. Plaintiff and his experts contended that Defendant Officer Aaron Green struck him with a nonlethal projectile to his head. Officer Green, along with the other named officer Defendants, was assisting in controlling a crowd of protestors. The protestors unlawfully protested in the Grand Park area after the Court declared an unlawful assembly and issued a dispersal order.

Defendants filed a motion to preclude the report and opinions of Plaintiffs’ biomechanics expert, John Gardiner, on the grounds that such evidence is irrelevant, improper, misstates the law, speculative, and would unduly prejudice Defendants.

Plaintiff opposes Defendants’ motion on the grounds that Gardiner’s opinions are based on the sworn testimony of Plaintiff and several Defendants. Additionally, Gardiner relied on video from body cameras and medical records. Plaintiff also argues that Gardiner is qualified to opine on the cause of Plaintiff’s injury because he is a biomechanics expert that has testified in other cases. 

Biomechanics Expert Witness

John Gardiner holds a Doctor of Philosophy in Bioengineering from the University of Utah and a Bachelor of Science in mechanical engineering from the University of Minnesota. He is a principal and senior biomechanical engineer at MEA Forensic. He joined the firm in 2002 and leads the Biomechanics Group in the Los Angeles office. Gardiner is responsible for conducting reconstruction and biomechanical analyses of a variety of events including automobile collisions, falls, sports injuries, and shootings. 

Get the full story on challenges to John Gardiner’s expert opinions and testimony with an in-depth Challenge Study

Discussion by the Court

Gardiner offered the following opinions:

1. The video evidence and testimony are consistent with Zuniga being located within a group of protestors on N Spring St. at the time he sustained this injury.
2. The video evidence and testimony indicate that multiple less-lethal rounds were fired in the general direction of Zuniga’s location north of the officers.
3. The horizontal nature of the laceration on the top of Zuniga’s head is consistent with contact from an approximately horizontally traveling less-lethal munition.
4. The description and appearance of Zuniga’s scalp laceration is consistent with contact by a bean bag round fired by Officer Green.

In forming his conclusions, Gardiner reviewed various materials. Specifically, these included body camera video, testimony, and medical records, all of which he analyzed in detail. As a result, his opinions were supported by the evidence available to him, as established in previous rulings.

The Defendants contended that Gardiner’s opinions were based on factual assumptions not supported by the record. They highlighted that, in his deposition, Gardiner admitted he could not specifically identify the Plaintiff in the video at the time of the shooting. Furthermore, he acknowledged that the Plaintiff might have moved from his last known location in the video before the less-lethal munitions were fired. However, the Plaintiff noted that Gardiner did not need to present his opinions with absolute certainty for his testimony to be admissible.

Held

The Court denied Defendants’ motion to exclude Plaintiffs’ biomechanics expert, John Gardiner’s opinions and testimony at trial.

Key Takeaways:

• Gardiner has an extensive background and experience in biomechanics. This qualifies him to testify regarding the cause of the Plaintiff’s injury.

• No part of Gardiner’s expert report indicated that any of his opinions are based on assumptions outside of the evidence provided. This includes body camera footage and medical records.

• Gardiner’s opinion regarding the horizontal nature of the laceration and its consistency with less-lethal munitions is not a legal conclusion. It is an expert analysis of the injury’s cause.

Please refer to the blog previously published about this case:

Law Enforcement Expert Witness is Qualified to Opine On Tactics and Uses of Force Employed by the Police

Case Details:

Case Caption:	David Zuniga V. City Of Los Angeles Et Al
Docket Number:	2:22cv3665
Court:	United States District Court for the Central District of California
Order Date:	September 18, 2024