Expert Witness Profiler

Tag: Mental Health

  • Law Enforcement Expert Allowed to Opine on Mental Health

    Law Enforcement Expert Allowed to Opine on Mental Health

    This case concerns a fatal officer-involved shooting that took place on February 5, 2023. Plaintiff Matilde Garza alleged that Defendants County of San Bernardino, Bill Abernathy, and Nicholas Krinder (collectively, “Defendants”) used excessive deadly force by shooting and killing Plaintiff’s son Antonio F. Garza, Jr. (the “Decedent”).

    Defendant filed motions to preclude the testimony of Plaintiff’s experts, John C. Hiserodt and Scott A. DeFoe.

    Pathology Expert Witness

    John Chatfield Hiserodt has performed over 12,000 autopsies in his career, including many cases of in-custody deaths and various types of shooting cases.

    He has been qualified as a Forensic Pathology Expert in determining cause, manner and mechanism of death in numerous trial venues throughout California and the country, including providing opinions regarding bullet trajectory in many shooting-related deaths.

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

    Law Enforcement Expert Witness

    Scott Allen DeFoe has twenty-eight years of law enforcement experience where he responded to hundreds of calls where subject may be barricaded, mentally ill, suicidal, experiencing a mental health crisis and worked almost 20 years with L.A.P.D’s mental evaluation unit.

    DeFoe also volunteered for five years with a suicide prevention hotline.

    Want to know more about the challenges Scott DeFoe has faced? Get the full details with our Challenge Study report.

    Discussion by the Court

    John Hiserodt

    Defendant sought to preclude Hiserodt from offering opinions regarding bullet trajectories and the position of the shooting officers relative to Garza. 

    Defendants argued that Hiserodt is not qualified in ballistics or crime-scene reconstruction so as to testify about such opinions and therefore, this evidence is inadmissible.

    Hiserdot has demonstrated his qualifications in similar cases and in medicine to form the basis of his opinion. Therefore, any probative value of such evidence is not substantially outweighed by danger of unfair prejudice, confusing the issues, or misleading the jury.

    Scott DeFoe

    Defendant sought to exclude any opinions by DeFoe regarding Garza’s alleged mental health crisis or mental illness. 

    Plaintiff submits evidence that beginning in 2020, Garza began to suffer mental health issues, and was experiencing a mental health crisis on the date of the incident.

    Defendant argued that DeFoe lacked the background, training, experience, or qualification to provide expert opinion testimony regarding Garza’s mental health status because DeFoe is not a psychiatrist, psychologist, counselor, or other individual with specialized knowledge which would allow him to opine on Garza’s mental health status at the time of the incident or his mental health history.

    At his deposition DeFoe stated he will not offer any opinion diagnosing Garza but rather how police officers in California are trained to recognize behavioral indicators associated with mental illness.

    The Court has reviewed DeFoe’s curriculum vitae and there is no reference to him being a medical provider but it stated that DeFoe has experience in crisis negotiations/mental health training.

    The Court found based on DeFoe’s resume, testimony and report that his experience is relevant to Plaintiff’s causes of action under the ADA and Rehabilitation Act.

    Held

    The Court denied the Defendants’ motions in limine to preclude the testimony of John C. Hiserodt and Scott Defoe.

    Key Takeaway

    Experts must be qualified to form the opinions that make up their testimony. DeFoe has sufficient experience in crisis negotiations/mental health training.

    Case Details:

    Case Caption: Matilde Garza V. County Of San Bernardino
    Docket Number: 5:23cv1849
    Court Name: United States District Court, California Central
    Order Date: February 19, 2026
  • Law Enforcement Expert Permitted to Testify on the General Reasonableness of Police Conduct 

    Law Enforcement Expert Permitted to Testify on the General Reasonableness of Police Conduct 

    This lawsuit can be traced back to an incident that took place on November 11, 2019, in which Phoenix Police Department Officer Brittany Smith-Petersen shot and injured Plaintiff Krish Singh during a law-enforcement encounter. 

    Defendants brought a partial Daubert motion seeking to preclude certain portions of the intended testimony of Plaintiff’s use-of-force expert, Roger Clark.

    Law Enforcement Expert Witness

    Roger Clark is a retired law enforcement professional with 27 years of experience in the Los Angeles County Sheriff’s Department (LASD). He was hired on December 1, 1965, and served until his retirement on March 31, 1993. Throughout his distinguished career, he held several key positions, including six years as a Deputy Sheriff, six years as a Sergeant, and 15 years as a Lieutenant. Roger retired with a California Peace Officer Standards and Training (POST) Advanced Certificate and is a graduate of the POST Command College, class #5, 1988.

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

    Discussion by the Court

    Ultimate-Issue Testimony

    To begin with, Clark’s assertion that the Officers’ conduct was “in violation of . . . law as taught to all officers” does more than simply provide an aid to the jury’s deliberation. It was, on its face, a legal opinion. Although the statement is technically qualified by the phrase “as taught to all officers,” the Court found such qualification insufficient and more likely to confuse than to illuminate.

    The rest of Clark’s report was more complex to evaluate. Many of the statements challenged by the Defendants use terms like “excessive” or “unreasonable.” These terms were tricky because they carried both everyday meanings and specific legal implications. It was appropriate for an expert like Clark to give opinions on what a reasonable police officer might do in a certain situation, based on standard training and professional norms. Using terms like “unreasonable” or “excessive” in that context does not automatically violate the Federal Rules of Evidence.

    However, Clark was not allowed to directly state that Officers Smith-Petersen or Batway acted unreasonably. Such a statement crossed the line from expert opinion into a legal conclusion, which is not permitted. Clark’s report walked a fine line—sometimes staying within proper boundaries, and other times crossing them.

    Most of the statements flagged by Defendants as improper could be corrected by rewording. Rather than examine every sentence now, the Court established a general rule and will address specific issues during the trial. Clark may testify about what constitutes reasonable or excessive force in general terms, but he may not say whether the specific officers in this case acted unreasonably or used excessive force.

    Mental Health Diagnoses

    Defendants argued that Clark’s report improperly offered an opinion about whether the Plaintiff was suffering from a mental disorder at the time of the incident. The Court disagreed, finding that this misrepresents the report. In the report, Clark explicitly stated that it is not the role or ability of police officers to diagnose a person’s disability. However, he also explained that officers are trained to recognize signs and cues that help them make appropriate decisions about how to respond. This training often involves mental health frameworks that guide officers in identifying possible mental health issues during their interactions with the public.

    Based on this training, Clark opined that the Officers should have recognized that the Plaintiff might be mentally ill or emotionally distressed—especially when the Plaintiff repeatedly asked them to kill him, a clear indication of mental distress. Clark’s testimony is not a clinical diagnosis. Instead, it is an expert opinion about how a trained officer should interpret observable behavior in the field. The Court found this type of opinion to fall well within Clark’s area of expertise.

    Defendants also took issue with a line in the report stating that the Plaintiff “suffered from PTSD, drug addiction, and ADHD.” But they failed to include the full context: that statement appears in the background section of the report and is explicitly attributed to the Plaintiff’s mother, Sunita Singh. Whether that statement qualifies as hearsay is not being decided here. What matters is that Clark himself did not diagnose the Plaintiff with any mental condition.

    Contravention of the Video Evidence

    Defendants’ final argument under Daubert is that Clark’s report relied on insufficient data because it allegedly contradicts the video footage of the incident. They claimed Clark misrepresented the facts by stating that the Plaintiff did not advance toward the officers, asserting instead that “the video clearly shows Singh advancing toward the officers multiple times.”

    Defendants also argued that Clark’s report was flawed because he claimed the officers failed to use de-escalation techniques. In contrast, Defendants insisted that they did employ such techniques, including issuing over twenty commands for the Plaintiff to drop his weapon or stop moving, speaking with him, and reassuring him that they did not believe he was mentally unstable.

    However, the Court found that most of Defendants’ arguments simply quoted portions of Clark’s report without explaining how those statements actually contradict the video evidence. Even in the few instances where Defendants attempted to point out specific inconsistencies, the Court found their arguments unconvincing.

    Held

    The Court granted in part and denied in part the Defendants’ partial Daubert motion to preclude certain portions of the intended testimony of Roger Clark.

    Key Takeaway:

    The Court ruled that while Clark may testify about general police practices and how a reasonable officer should interpret signs of mental distress, he may not offer legal conclusions—such as stating that the officers acted unlawfully or unreasonably. His mental health observations were deemed within his expertise and not clinical diagnoses. The Court also rejected Defendants’ argument that Clark’s report contradicted video evidence, finding their objections vague and unpersuasive.

    Case Details:

    Case Caption: Krish Singh V. City of Phoenix
    Docket Number: 2:21cv99
    Court Name: United States District Court, Arizona
    Order Date: June 12, 2025
  • Anesthesiology Expert Barred from Testifying About Alleged Strip Search

    Anesthesiology Expert Barred from Testifying About Alleged Strip Search

    The claims against La-Norma Ramirez and Washington County stem from Plaintiff Danyale Blackmore’s booking and release at the Washington County Jail.

    Blackmore alleged that her constitutional rights were violated when she was allegedly strip-searched at the Jail.

    Defendant sought to exclude or limit at trial the testimony of Plaintiff’s expert, Dr. Scott Allen. 

    Anesthesiology Expert Witness

    Scott Allen is a licensed medical doctor with specialization in anesthesiology. He has been board certified since 2017 by the American Board of Anesthesiology.

    Allen currently practices as an anesthesiologist with Mountain West Anesthesiology and has privileges at Intermountain Health Care, specifically at St. George Regional Hospital in St. George, Utah and Intermountain Medical Center in Salt Lake City, Utah.

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

    Discussion by the Court

    Plaintiff received multiple ketamine treatments at Allen’s clinic, starting on October 5, 2020, and met with Allen during at least three of her visits to the clinic.

    Allen was retained to testify that the Plaintiff’s arrest and the events surrounding it were extremely traumatic for her, leading to serious psychological and emotional issues.

    Plaintiff fails to demonstrate the reliability of Allen’s testimony for some of the matters for which he was designated as an expert

    The Defendant argued that Allen’s methods and opinions are unreliable because ketamine is not widely accepted as a standard treatment within the medical community. They also noted that Allen had only a few treatment sessions with the Plaintiff and based his understanding of her condition primarily on her ketamine treatment records.

    However, in his deposition, Allen explained that ketamine is a recognized treatment for certain medical and mental health conditions. He also testified that he used specific criteria and relied on sufficient facts to conclude that the Plaintiff exhibited symptoms consistent with anxiety, depression, or PTSD.

    Despite this, Allen did not provide an adequate basis to formally diagnose the Plaintiff with any medical or mental health condition. He also lacked personal knowledge of her arrest and alleged strip search. Ultimately, Allen did not diagnose the Plaintiff and cannot reliably determine the cause of her symptoms or the source of any diagnoses she may have received.

    Allen’s anticipated testimony, as limited in scope, is relevant and admissible

    The Defendant argued that even if Allen’s testimony meets the standards of Rule 702, it is irrelevant because it would not help the jury decide whether the Plaintiff was strip searched.

    Allen will not be allowed to testify that the strip search occurred or that it caused the Plaintiff to develop PTSD or any other medical or mental health condition. He also may not vouch for the Plaintiff’s credibility or state that he believes her version of events is true. However, this does not mean that his testimony is irrelevant to the issues at trial.

    Allen is permitted to testify about his direct observations of the Plaintiff during her ketamine treatments, as well as his communications with her during those sessions. Such testimony is generally not considered hearsay. If a proper foundation is laid and the testimony otherwise meets the requirements of the Federal Rules of Evidence, the Court held that Allen may also testify about general matters such as mental health diagnoses and the Plaintiff’s potential need for future ketamine treatments.

    This testimony is highly relevant to the issue of damages and may also be used to rebut the opinions and testimony of the Defendant’s expert, provided it meets evidentiary standards.

    Held

    The Court granted in part and denied in part the Defendant’s motion to exclude or limit the testimony of Dr. Scott Allen.

    Key Takeaway:

    It is important to note that Allen never diagnosed the Plaintiff with any specific medical or mental health condition. While he may speak generally about medical and mental health diagnoses, he is not permitted to testify or offer an opinion that the Plaintiff has, or is suffering from, any specific condition such as anxiety, depression, or PTSD.

    Please refer to the blogs previously published about this case:

    Mental Health Expert’s PTSD Diagnosis Was Deemed Reliable

    Corrections Expert’s Opinions on the Strip Search Excluded

    Social Work Expert’s Testimony on PTSD Symptoms in Adult Women Admitted

    Family Medicine Expert’s Opinions on Opposing Experts’ Qualifications Excluded

    Case Details:

    Case Caption: Blackmore V. Ramirez
    Docket Number: 4:21cv26
    Court Name: United States District Court, Utah
    Order Date: May 27, 2025
  • Pediatrics Expert Witness’ Psychological Diagnoses of the Three Children Admitted

    Pediatrics Expert Witness’ Psychological Diagnoses of the Three Children Admitted

    Respondent traveled with her three minor children, J.H., A.H., and S.H., from Mexico to the United States in 2022. Petitioner sought the return of his minor children to Mexico under the Hague Convention. Respondent called Dr. Minal Giri to testify as an expert witness on July 16 and Dr. Paul Gillingham to testify as an expert witness on August 5. Petitioner reserved his objections during the hearing and now moves to exclude the opinions and testimony of Giri and Gillingham.

    Pediatrics Expert Witness 

    Minal Giri is a licensed pediatrician with a medical degree from the University of Chicago. She has been a practicing pediatrician for over twenty years, since she completed her residency at Lutheran General Hospital in 2002. As part of her training, she studied mental health and mental trauma experienced by children. And as part of her current practice, she sees and treats children suffering from mental health conditions such as anxiety and depression on a regular basis. She completed a Global Mental Health Certificate at Harvard University in 2020 that focused on refugee trauma and recovery. 

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

    History Expert Witness 

    Paul Gillingham is a Professor in the History and Spanish & Portuguese Departments of Northwestern University and holds a Ph.D in the history of modern Mexico.

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

    Discussion by the Court

    Minal Giri

    In her report and testimony, Giri diagnosed J.H. with post-traumatic stress disorder (“PTSD”) and generalized anxiety disorder, A.H. with PTSD and generalized anxiety disorder, and S.H. with separation anxiety disorder. She opined that if the three children were to return to Mexico, this would compound their existing trauma and exacerbate their disorders. 

    Qualifications

    First, Petitioner argued that Giri is not qualified to provide psychological diagnoses because she is neither a psychiatrist nor a psychologist. But Giri has specific experience diagnosing and treating mental health and mental trauma for immigrant and refugee children. She has written expert reports for approximately 35 prior cases, each of which involved the mental evaluation of children or adults seeking asylum and immigration relief. The Court held that Giri is qualified to provide psychological diagnoses for the three children.

    Methodology

    Petitioner challenged Giri’s methodology. Primarily, Petitioner argued that Giri’s methodology was flawed because she did not ask questions during the interviews about possible causes of the children’s symptoms, beyond their father’s alleged mistreatment. Moreover, Petitioner contended that Giri’s reliance on the Istanbul Protocol implies a false assumption by Giri that the children had been traumatized. 

    The Court held that Giri’s methodology was sound. She interviewed J.H., A.H., and S.H. consistent with her training as a pediatrician and reached conclusions based on those interviews.

    Petitioner also argued that Giri’s methodology was flawed because the DSM-5 contains eight requirements for a PTSD diagnosis and Giri’s reports for J.H. and A.H. enumerated just five of these requirements. The Court held that Petitioner’s cross-examination was the appropriate remedy to attack the missing information rather than exclusion of Giri’s entire report.

    Petitioner argued that Giri’s methodology was flawed because Giri was not present when J.H. and A.H. filled out the GAD-7 and PHQ-9 questionnaires (screening tests for mental health conditions) and thus had no way to verify their answers. Giri testified that her diagnoses were based on the interviews, not the questionnaires, and that the questionnaires merely confirmed the diagnoses she had already reached based on the interviews. The Court affirmed the admissibility of the diagnoses.

    Paul Gillingham

    In his report and during his testimony, Gillingham offered an opinion on 1) the general level of violence in Respondent’s hometown of Zitácuaro; 2) whether, based on his understanding of Mexico and Zitácuaro, Respondent’s allegations of violence were credible; and 3) whether, based on his understanding of Mexico and Zitácuaro, Respondent would have been able to rely on the police or court system for recourse in her divorce case or for physical protection.

    First, Petitioner argued that Gillingham’s report should be excluded because Gillingham failed to disclose all his sources. The Court held that this particular nondisclosure does not warrant exclusion of the entire report. Gillingham testified that he had relied on three data points in forming his opinion about violence in Zitácuaro: homicide rates, internally displaced persons, and disappearances. Gillingham’s report disclosed homicide rates but failed to disclose anything about internally displaced persons or disappearances. Overall, Gillingham’s eighteen-page report contains thorough citations with fifty-eight footnotes. Moreover, Petitioner’s counsel effectively and extensively cross-examined Gillingham on this issue. The Court found that Petitioner fully cured any prejudice stemming from the non-disclosure and thus that the non-disclosure was harmless.

    Second, Petitioner argued that Gillingham’s report and testimony should be excluded as unreliable and irrelevant because Gillingham failed to rely on facts specific to this case. However, Gillingham’s mission was to take the allegations made by Respondent and to assess their general plausibility given what he knows, as an expert, about the political and criminal situation in Zitácuaro. The Court held that the nature of Gillingham’s testimony is unusual. It is less of an analysis and more a sharing of information about Zitácuaro. But there is nothing to suggest that the information provided by Gillingham is flawed. The Court found it at least minimally relevant and thus admissible.

    Held

    The Court denied the Petitioner’s motions to exclude the opinions and testimony of Minal Giri and Paul Gillingham.

    Key Takeaway:

    • All expert opinions come with assumptions and conclusions. Petitioner is free to disagree with Giri’s assumptions and conclusions, but that does not render Giri’s testimony inadmissible.
    • There is nothing to suggest that the information provided by Gillingham is flawed. And his testimony is at least minimally relevant to provide the Court with context for Respondent’s hometown of Zitácuaro. Whether the Court will ultimately afford Gillingham’s testimony much weight in deciding this case is an open question. The testimony, however, is at least minimally relevant and thus admissible.

    Case Details:

    Case Caption: Delgado Moreno V. Hernandez Escamilla
    Docket Number: 1:23cv15736
    Court: United States District Court for the Northern District of Illinois, Eastern Division
    Order Date: August 27, 2024