Biomechanics Expert Was Allowed to Opine on the Source of Bullet Wounds
Posted on November 13, 2025 by Expert Witness Profiler
This suit involves the unnecessary use of excessive force by police officers against a black man suffering from a mental health crisis.
On November 21, 2021, during a mental health crisis, Jabari Asante-Chioke encountered Louisiana State Police (“LSP”) Officer Nicholas Dowdle and East Jefferson Levee District (“EJLD”) Officers Jonathon Downing and Gerard Duplessis (collectively referred to herein as “Officer Defendants”
Plaintiff, Malikah Asante-Chioke, individually, and on behalf of her father, Jabari Asante-Chioke, herein filed this action against the Defendants, accusing them of failure to use less-than-lethal methods in accordance with training and state and federal law, to subdue Mr. Asante-Chioke.
LSP Defendants argued that the Court should exclude Plaintiff’s expert John C. Gardiner, along with his testimony and opinions, because he is unqualified, his methodology is unreliable, and his testimony is irrelevant.
EJLD Defendants made similar arguments, but they also argued that Gardiner’s testimony will not help the factfinder.
Biomechanics Expert Witness
Dr. John Carter Gardiner, PhD PE holds a Bachelor of Science in Mechanical Engineering and a Doctor of Philosophy in Bioengineering. He is a Senior Biomechanical Engineer who conducts biomechanical analysis of a variety of events including shootings.
Gardiner 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.
Discussion by the Court
I. Gardiner’s Qualifications
LSP Defendants argued that Gardiner is unqualified to opine on the likely source of the shots fired because, apart from his expert reviews, he lacked specific training, education, or experience analyzing bullet trajectory “based on gunshot wounds.”
Gardiner estimates that he has performed biomechanical analyses in “50 different cases involving” gunshot wounds.
LSP Defendants offered no authority which requires Senior Biomechanical Engineers to have specific training, experience, or education in bullet trajectory analysis to opine on the source of each bullet wound. Further, courts have allowed biomechanical engineers, including Gardiner, to opine on the source of wounds in a shooting.
Accordingly, the Court found that Gardiner is qualified to opine on the likely source of Mr. Asante-Chioke’s gunshot wounds.
II. Reliability of Gardiner’s Methodology
LSP Defendants also argued that Gardiner’s methodology is unreliable because he did not calculate or quantify the officers’ exact shooting angles.
Plaintiff contended that Gardiner did not merely “eyeball” the footage and instead considered “the relative positions of each of the three officers to Asante-Chioke, the gunshot wound entrances and exits, the gunshot wound trajectories, and the anatomical postures and positions of Asante-Chioke during the shooting incident.”
This Court agreed with Plaintiff. LSP Defendants offered no authority which requires an expert to quantify or calculate exact shooting angles to opine on shooting source and position.
LSP Defendants also argued that Gardiner’s methodology is unreliable due to alleged inconsistencies and contradictions concerning the timing of certain wound in his report termed as Gunshot Wounds #14 and #15 and his conclusions concerning how many gunshot wounds were consistent with coming from Dowdle during the final 1.1 seconds of the shooting. However, as Plaintiff correctly pointed out, LSP Defendants primarily disputed Gardiner’s conclusions, not his methodology.
III. Relevance of Gardiner’s Opinions
Defendants argued that Gardiner’s opinions are irrelevant to the issue of qualified immunity at this stage of the litigation. LSP Defendants also suggested that Gardiner opined on ultimate causation and damage issues regarding Gunshot Wound #15.
This Court found that most of Gardiner’s opinion is relevant. In his report, Gardiner opines on the likely source of Asante-Chioke’s bullet wounds and when the shooting officers, including Dowdle, likely fired them. Such opinions are relevant to the pertinent qualified immunity issues of “whether Dowdle fired any shots; how many if so; and when, in relation to Asante-Chioke’s actions and death.”
Still, in his report Gardiner also references Chief Forensic Pathologist Dr. Dana Troxclair’s conclusion that the “bullet causing Wound #15 killed Mr. Asante-Chioke.” Opinions and references thereto concerning which bullet killed Asante-Chioke are irrelevant to the limited issue of whether the shooting officers are entitled to qualified immunity when they continued to fire upon him. Accordingly, the Court excluded such opinions and references from Gardiner’s report.
IV. Helpfulness of Gardiner’s Opinions
EJLD Defendants also argued that Gardiner’s testimony will not assist the factfinder because video captures the incident.
Plaintiff argued that neither of EJLD Defendants’ cited cases mention the use of experts or hold that experts cannot assist the factfinder in interpreting facts depicted on video. The Court agreed with Plaintiff.
By opining on the likely source and timing of each gunshot wound, Gardiner will help the factfinder determine whether each of the shooting officers acted unreasonably when they continued to fire upon Asante-Chioke.
Held
- The Court granted in part and denied in part the LSP Defendants’ motion to exclude the testimony and opinions of John Gardiner.
- The Court denied the EJLD Defendants’ motion to exclude the testimony of Plaintiff’s expert John C. Gardiner.
Key Takeaway:
While Gardiner will be allowed to testify as an expert in this case, but he will not be able to opine or reference opinions on which wound likely killed Asante-Chioke.
Opinions and references thereto concerning which bullet killed Asante-Chioke are irrelevant to the limited issue of whether the shooting officers are entitled to qualified immunity when they continued to fire upon him.
Case Details:
| Case Caption: | Asante-Chioke V. Dowdle Et Al |
| Docket Number: | 2:22cv4587 |
| Court Name: | United States District Court, Louisiana Eastern |
| Order Date: | November 12, 2025 |
