Psychiatry Expert Was Barred From Testifying About the Abuse Allegations
Posted on November 25, 2025 by Expert Witness Profiler
From 2020 to 2022, Plaintiff Jane Doe was dating Defendant Aaron Tanner, who at the time was a member of the Los Angeles County Sheriff’s Department (“LASD”) and the alleged leader of a law enforcement gang called the “Rattlesnakes.”
According to Plaintiff, during the course of her relationship with Tanner, Tanner physically abused her. Tanner also warned Plaintiff that, “if she told anyone” about his abuse, the Rattlesnakes would “take care of her.”
Plaintiff alleged that, after she broke up with Tanner in 2022, he and other members of the Rattlesnakes began to stalk and intimidate her. In 2023, the LASD’s Internal Affairs Bureau interviewed Plaintiff in connection with an “investigation into Tanner and a deputy who was stopped for a DUI by Tanner.” Later that year, the LASD’s Internal Criminal Investigations Bureau formally opened an investigation on Tanner. Soon after, law enforcement officers began to surveil Plaintiff’s home and, in one instance, “the gas tank of her car was tampered with, in an apparent effort to cause her to crash her car.” The LASD has since terminated Tanner’s employment, but Plaintiff alleges Tanner continues to stalk her, and she fears further retaliation from the Rattlesnakes.
The County filed motions to exclude the testimony of Dr. George Elias and Mr. Roger Clark, who Plaintiff has named as a psychiatric expert and as a police practices expert, respectively.
Psychiatry Expert Witness
Dr. George R. Elias is certified by the American Board of Psychiatry and Neurology in both Adult and Forensic Psychiatry. He is licensed to practice medicine in the states of California and Missouri.
He is also licensed as an Out-of-State Telehealth Provider in Florida. Elias has provided expert opinion on various criminal and civil matters through written reports, testimony, and deposition. Elias is currently the President of Elias Diagnostix, a private forensic and outpatient psychiatric practice.
Law Enforcement Expert Witness
Roger Clark has worked as a Deputy Sheriff, Sergeant, and Lieutenant in the LASD over the span of a 27-year career.
Clark frequently spoke out about law enforcement gangs, drafted an internal memorandum addressing the topic, and spoke with various LASD executives to voice his concerns.
Since retiring from the LASD in 1994, Clark has worked as a police practices consultant and has been retained in over 2,600 cases.
Discussion by the Court
A. Discovery Sanctions
The County argued that Elias and Clark should not be permitted to testify because the Plaintiff failed to disclose either expert by the July 30, 2025, deadline set out in the Court’s December 26, 2024, Scheduling Order.
Instead, Plaintiff disclosed Elias as an expert on August 4, 2025, and served his expert report on August 13, 2025—the deadline for either party to designate rebuttal experts. Plaintiff also identified Clark as an expert on August 4, 2025, serving Clark’s initial report the same day and a revised copy of his report on August 8, 2025.
Here, Plaintiff disclosed both Elias and Clark as experts five days after the deadline set out in the Court’s Scheduling Order, served Clark’s report the same day, and served Elias’ report approximately nine days later, all before the close of expert discovery and more than a month before the deadline to file a motion for summary judgment.
True, Plaintiff’s delay prevented the County from naming a rebuttal witness to Elias by the deadline set out in the Court’s Scheduling Order. However, even though expert discovery is now closed, Plaintiff has offered to enter into a stipulation that would allow the County to designate a rebuttal expert. Moreover, notwithstanding Plaintiff’s delay, Defendant designated a rebuttal expert to respond to Clark’s opinions and deposed both Elias and Clark.
Given the minimal harm from Plaintiff’s untimely disclosure, Defendant’s opportunity to cure that harm through measures short of exclusion, the lack of any substantial impact on the trial schedule, and the absence of any indication Plaintiff acted willfully or in bad faith, the Court found Plaintiff’s untimely disclosure harmless and declined to exclude either Elias or Clark on that basis.
B. George Elias
Plaintiff offered Elias as an expert on “Plaintiff’s psychological condition, stress, and emotional and mental damages.”
Elias offered proposed testimony that (1) Plaintiff “meets DSM-5 Diagnostic Criteria for Post-Traumatic Stress Disorder [(“PSTD”)], with dissociative symptoms”; (2) Plaintiff “suffered from severe emotional distress that was a result of [Tanner’s] conduct”; and (3) Plaintiff’s “Post-Traumatic Stress Disorder is attributable to the severe emotional distress she endured.”
Analysis
The Court disagreed that Elias’ opinions are unsupported by a reliable methodology. Elias conducted a four-hour interview of Plaintiff, during which he “obtained a longitudinal history of Plaintiff, which included the onset, course, and severity of [her] symptoms, along with any associated clinically significant dysfunction.”
Before diagnosing Plaintiff with PTSD, Elias “considered her medical history,” “reviewed her psychotherapy records,” and “performed a differential diagnosis.” Before reaching his diagnosis, Elias screened out “bipolar spectrum disorder, a prior history of depression, and substance use issues” as possible causes of Plaintiff’s symptoms. Finally, Elias reached a diagnosis based on the diagnostic criteria set out in the DSM-5.
The County argued that this is not enough, because Elias “did not obtain collateral information from family members, co-workers, or treating providers” and “did not administer any standardized tests commonly used in psychiatric evaluations, such as the CAPS-5, PCL-5, or MMPI-2.”
However, these criticisms go to the weight of Elias’ testimony, not its admissibility.
Nevertheless, the Court agreed that Elias may not testify that Tanner’s conduct “caused” Plaintiff’s PTSD. As an expert witness, Elias has no personal knowledge of Tanner’s conduct and cannot testify as to the credibility of Plaintiff’s specific allegations of abuse.
C. Roger Clark
Clark offered seven opinions: (1) Tanner used “excessive force” by “choking out” Plaintiff; (2) the “Rattlesnakes are a subgroup in LASD operating out of the Lancaster Station”; (3) the “Rattlesnakes meet the definition of a deputy gang,” as determined by Clark; (4) “Tanner’s references to the [R]attlesnakes in conversation with [Plaintiff] would intimidate a witness”; (5) Clark has not seen any evidence that would justify Tanner’s use of force under Peace Officer Standards and Training (“POST”) or LASD policies; (6) the LASD tolerates deputies’ use of excessive force, fails to properly investigate excessive force complaints, and fails to properly investigate and discipline membership in law enforcement gangs; and (7) the “collective approvals by the LASD puts the general public at unnecessary future risk of death and/or injury from the Defendant Deputies” and others in the LASD.
Analysis
The County argued that Clark is not qualified to testify on law enforcement gangs, six of his seven opinions amount to improper legal conclusions, his fourth opinion is not supported by a reliable methodology, and his seventh opinion is subject to exclusion under Rule 403.
As a preliminary matter, Clark is adequately qualified to testify as to law enforcement gangs within the LASD.
However, the Court agreed that four of Clark’s seven proposed opinions are improper. To start, Clark may not testify that “Deputy Tanner’s references to the Rattlesnakes in conversations with Plaintiff would intimidate a witness.” Nothing in Clark’s experience qualifies him to testify as to what “would intimidate a witness” and, to the extent Clark proposed to testify as to whether Tanner in fact intimidated Plaintiff, his proposed testimony improperly speculated as to Plaintiff’s state of mind.
Likewise, Clark may not testify that the “collective approvals by the LASD put the general public at unnecessary future risk of death and/or injury from the Defendant Deputies and others in the department,” because this proposed testimony would not be helpful to the jury and added nothing beyond the sixth opinion set out in his report.
Next, Clark’s opinions addressing the use of “excessive” and “unreasonable” force amounted to legal conclusions. To the extent such testimony is relevant, Clark may only testify as to whether Tanner’s use of force conformed to POST standards and LASD policies.
The Court rejected the County’s argument that Clark’s remaining opinions are legal conclusions. Indeed, the County has not sufficiently explained how any of the terms Clark used in those opinions “have a specialized meaning in law” or how Clark has “attempted to instruct the jury on the law” or to “apply the law to the facts of the case.”
Held
The Court granted in part and denied in part the Defendant County of Los Angeles’s motions To exclude Dr. George Elias and Roger Clark.
Key Takeaway:
While Elias did not obtain collateral information from family members, co-workers, or treating providers, Elias is an experienced medical professional, the DSM is a recognized source of authority within the psychiatric community, and the County did not argue that Elias has misapplied the DSM.
Case Details:
| Case Caption: | Jane Doe V. County Of Los Angeles |
| Docket Number: | 2:24cv8649 |
| Court Name: | United States District Court, California Central |
| Order Date: | October 28, 2025 |
