Expert Witness Profiler

Tag: Pepper Spray

  • Law Enforcement Expert’s Testimony on the Use of Pepper Spray Limited

    Law Enforcement Expert’s Testimony on the Use of Pepper Spray Limited

    Plaintiff LaBlanca Sibley’s excessive force claim against Officer Nicholas S. Riggall, arising from her arrest and detention, was based on Riggall’s use of pepper spray while she was seated in the patrol car.

    Sibley retained Mr. Jeronimo Rodriguez, an expert in law enforcement practices and use-of-force standards. Riggall moved to exclude Rodriguez’s opinions and testimony. Riggall challenged Rodriguez’s qualifications, methodology, and helpfulness to the trier of fact.

    Law Enforcement Expert Witness

    Jeronimo “Jerry” Rodriguez served as a police officer with the Los Angeles Police Department for over 25 years, including work in the Force Investigation Division.

    Since retiring as an active law enforcement officer in 2021, Rodriguez has reviewed and consulted on police and law enforcement practices as a private police consultant and audited agencies across the country and continued to train many agencies throughout the United States on police-related investigations.

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

    Discussion by the Court

    Qualifications

    Riggall pointed out that Rodriguez has not “studied, personally conducted research, or authored any literature on the use of force at issue in this case.”

    First, Riggall’s argument on qualifications, made conclusorily and without citations to any authority, is insufficiently developed for the Court to consider.

    Regardless, Rodriguez is qualified to testify as a police practices expert generally and about the use of force specifically. Rodriguez has served as a law enforcement officer for decades. For some of those years, he conducted investigations into officers’ uses of force. Since his retirement from law enforcement, Rodriguez has worked as a police practices expert in other cases and has consulted and provided trainings on various police practices subjects.

    Reliability

    Riggall argued that Rodriguez’s opinions “are not based on sufficient or accurate data” because, among other things, Rodriguez supposedly “draws his opinion on the force being excessive largely upon his belief that Sibley was falsely arrested and had not been resisting or involved in any crime.”

    The Court found Rodriguez’s methodology sufficiently reliable. Rodriguez described his methodology thusly: his “method for forming opinions relies on nearly forty years of experience as a police officer and trainer, collaboration with various instructors and police practices experts, and a comprehensive review of relevant evidence and materials, without making credibility judgments.”

    To the extent Rodriguez allegedly relied on Sibley’s version of events, such reliance did not merit exclusion of Rodriguez’s opinions.

    Assistance to the Trier of Fact

    Riggall argued that Rodriguez’s opinions will not be helpful to the jury because “Rodriguez never explains, beyond his own characterization of Plaintiff’s behavior as ‘tapping merely to get an officer’s attention to plead her innocence,’ the basis for not permitting a reasonable officer to interpret Plaintiff’s behavior as violent or aggressive.” He also argued that “Rodriguez offered legal opinions in the guise of interpreting the [Lakeland Police Department’s] policy on use of force.”

    However, the Court rejected this argument in part. Rodriguez’s opinions on the use of force and police practices will be helpful to the jury. Likewise, Rodriguez’s opinion on whether Riggall behaved in accordance with police procedures will be helpful to the jury.

    Although most of Rodriguez’s opinions and report do not contain legal conclusions, he did characterize the use of pepper spray as “excessive.” Calling the use of force “excessive” is a legal conclusion, given the jury is tasked with deciding whether the use of force was “excessive” and, therefore, unconstitutional. As a result, the Court will not allow Rodriguez to opine that the use of force was “excessive.” 

    Held

    The Court granted in part and denied in part the Defendant Nicholas S. Riggall’s motion to exclude the testimony of Plaintiff’s expert Jeronimo Rodriguez.

    Key Takeaway

    An expert is permitted to base his opinion on a particular version of disputed facts and the weight to be accorded to that opinion is for the jury.

    Case Details:

    Case Caption: Sibley V. City Of Lakeland
    Docket Number: 8:24cv2853
    Court Name: United States District Court, Florida Middle
    Order Date: January 27, 2026
  • OSHA Expert Barred From Testifying About Causation

    OSHA Expert Barred From Testifying About Causation

    David Badagliacco, a Skokie, Illinois police officer, sued Safariland, LLC, alleging his exposure to pepper spray during their training course was the reason he suffered from an eye infection necessitating cornea replacement surgery. Badagliacco contended that the negligent, willful and wanton operation of the training course caused his injuries.

    Plaintiff David Badagliacco retained expert witness Patrick Schuerman, an inspector for the Illinois Occupational Safety and Health Administration to testify regarding the standard of care for provision of a decontamination station when training for use of a substance like pepper spray. 

    Badagliacco’s treating physician, Ali Djalilian, an ophthalmologist and corneal specialist, offered an opinion about whether pepper spray can cause the injury Badagliacco suffered. 

    Safariland argued that there is insufficient evidence for a reasonable jury to find that any breach of Safariland’s duty with respect to provision of a decontamination station caused Badagliacco’s injuries. Specifically, Safariland argued that neither: (1) the OSHA inspector, Patrick Schuerman; nor (2) Badagliacco’s treating physician, Ali Djalilian, are qualified to offer an opinion regarding the causation of the injuries to Badagliacco’s eyes.

    Occupational Safety and Health Administration Expert Witness

    Patrick Schuerman is a member of Midwest Safety Consultants LLC. He has
    expertise in workplace safety, accident investigations, and State and Federal
    Standards as it relates to Occupational Health and Safety. He has had 30 years of Safety and Risk Management Experience. In addition, he has been an instructor at Illinois Valley Community College, teaching industrial safety since 2012.

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

    Ophthalmology Expert Witness

    Ali R. Djalilian is a recognized authority on immunologic issues in corneal/limbal stem cell transplantation and the surgical management of severe ocular surface disease. He has developed innovations in surgical techniques that substantially improve the surgical efficiency and the patient outcomes. Djalilian bridges his clinical experience with his basic science and translational research projects, which have been funded in part by the National Eye Institute/NIH and Research to Prevent Blindness. He joined the department in 2005. He is board certified in ophthalmology.

    Discover more cases with Ali R. Djalilian as an expert witness by ordering his comprehensive Expert Witness Profile report. 

    Discussion by the Court

    The Court agreed that Schuerman lacked the necessary expertise to testify about the cause of an eye injury. However, Schuerman’s testimony is intended to address the standard of care for provision of a decontamination station, not causation of Badagliacco’s eye injury. The Court does not understand Badagliacco to be offering Schuerman’s testimony to prove causation. Safariland had not challenged his qualification on the standard of care issue, and the Court found him qualified for that limited purpose. The causation of Badagliacco’s eye injury, however, implicates the physiology of the human eye, and Badagliacco has not argued that Schuerman has any expertise in that subject area, so the Court barred him from testifying about it.

    Djalilian has treated Badagliacco’s eye injuries, and therefore was qualified to offer an opinion about whether pepper spray can cause the injury Badagliacco suffered. 

    The Court rejected Safariland’s argument that Djalilian was not qualified to opine on whether the “pepper spray could injure the eye such that an infection could develop” because he is not a toxicologist or epidemiologist.  Toxicologists or epidemiologists are generally not experts in the physiology of the eye.

    The Court held that this argument concerned the weight of Djalilian’s testimony, not its admissibility.

    Held

    While there is nothing about Patrick Schuerman’s expertise that would qualify him to offer an opinion about the cause of an eye injury, the Court found him qualified to testify about the standard of care for provision of a decontamination station.

    As for Ali Djalilian, the Court held that he is an expert in the functioning of the human eye, and thus qualified to offer an opinion about whether pepper spray can cause the injury Badagliacco suffered. 

    Key Takeaway:

    A treating physician’s opinion about causation is admissible without disclosure as opinion evidence pursuant to Federal Rule of Civil Procedure 26(a)(2), as long as the physician made the determination about the cause of the injury “in the course of providing treatment.”

    Djalilian testified that in the course of his treatment of Badagliacco’s injuries he determined that they were caused by the pepper spray.

    Case Details:

    Case Caption: Badagliacco v. Safariland, LLC
    Docket Number: 1:21cv2424
    Court Name: United States District Court for the Northern District of Illinois, Eastern Division
    Order Date: May 9, 2025
  • Law Enforcement Expert May Provide Testimony about the National and SLMPD Standards for the Use of Pepper Spray

    Law Enforcement Expert May Provide Testimony about the National and SLMPD Standards for the Use of Pepper Spray

    Rev. Darryl Gray is suing the City of St. Louis and two St. Louis Metropolitan Police Department (SLMPD) detectives—Ronald Vaughan and Larry Wentzel—for violating his First and Fourth Amendment rights, as well as a variety of state law torts. 

    To support his constitutional claims, Rev. Gray hired Greg Meyer to give his expert opinion on some of the issues in the case. 

    Meyer’s expert report sets out his extensive experience in law enforcement, and Defendants do not challenge his qualifications. Instead, Defendants filed a motion to exclude five opinions in Meyer’s report as unreliable and not helpful to the jury.

    Law Enforcement Expert Witness

    Greg Meyer has 47 years of law enforcement experience, including 33 years as a police tactics and procedures consultant.

    He has been an expert witness in numerous high-profile cases including Rodney King, Oscar Grant (the Oakland BART murder case), and George Floyd. He has been engaged in more than 400 civil and criminal cases as well as conducting outside independent reviews of use of force cases for a federal prosecutor and several district attorneys and police chiefs.

    Discover more cases with Greg Meyer as an expert witness by ordering his comprehensive Expert Witness Profile report.

    Discussion by the Court

    Opinions 2 and 3 are excluded because the City was granted summary judgment

    Opinions 2 and 3 in Meyer’s report relate to Rev. Gray’s Monell claims against the City of St. Louis.

    After the motion to exclude was filed, the Court granted summary judgment to the City on Rev. Gray’s Monell claim. Opinions 2 and 3 in the report are therefore excluded because they will not “help the trier of fact to understand the evidence or to determine a fact in issue.” 

    Meyer’s Opinions

    Meyer’s first opinion is:

    “If the “Defendants’ actions violated Plaintiff’s First Amendment rights to freedom of speech and freedom of assembly by interfering with Plaintiff’s ability to associate freely in public and express Plaintiff’s views as part of a peaceful demonstration” as described in Para. 89 of the Second Amended Complaint, then the Defendants’ actions did not conform with proper contemporary law enforcement procedures.”

    Meyer’s fourth opinion is:

    “If Plaintiff did not push or otherwise assault or engage in preassault indicators against Defendant Vaughan’s allegedly pushing Plaintiff and using pepper spray on Plaintiff, and Officer Wentzel’s allegedly tackling Plaintiff to the street, did not conform with SLMPD policy or contemporary law enforcement training or procedures, and the resulting arrest and prosecution of the Plaintiff was false and malicious.”

    Meyer’s fifth opinion is:

    “If Plaintiff Gray did not assault Detective Vaughan, then both Detective Vaughan and Officer Wentzel appear to have violated SLMPD use of force policy and generally accepted police procedures when Detective Vaughan pepper sprayed Plaintiff Gray at extreme close range (inches); and Officer Wentzel used unnecessary and unreasonable force on Plaintiff Gray when he took him to the ground.”

    Opinion 1 is Excluded Because it is not Helpful to a Jury

    Defendants argued that his opinion will not be helpful to the jury because it is not based on “any specialized, scientific, or technical knowledge.” They claimed that the opinion says nothing more than “if the officers did it wrong, then they did it wrong.” The Court agrees with the Defendants.

    Meyer’s opinion as formulated in his report tells the jury only that if Defendants’ conduct violated Rev. Gray’s First Amendment rights, then it did not conform with contemporary law enforcement procedures. 

    The Court ruled that Meyer’s first opinion does not provide any additional insight into police practices that might be helpful to the jury. His rationale for Opinion 1 makes that clear. The police procedures and practices he cites are a restatement of First Amendment law. Meyer does not even opine that he thinks Defendants’ conduct violated the First Amendment under the circumstances. He admits that the facts are disputed, and he cannot determine who is correct.

    Opinions 4 and 5 are Excluded to the Extent that they State Legal Conclusions

    In Opinion 4, Meyer’s analysis of law enforcement training is just a description of the Fourth Amendment and Supreme Court precedent. The Court determined that Meyer relied on the Constitution and Supreme Court precedent to form opinions on questions of law that will not “help the trier of fact to understand the evidence or to determine a fact in issue.”

    In his rationale for Opinion 5, Meyer goes into more detail about SLMPD policy and accepted police procedure on the use of pepper spray but provides no analysis for his opinion that “Officer Wentzel used unnecessary and unreasonable force on Plaintiff Gray when he took him to the ground.”

    Plaintiff argued that Meyer’s opinions are not legal conclusions because they provide “the jury with a framework for placing the jury’s own findings in the context of national police standards and SLMPD policies.”

     In his rationale for Opinion 5, Meyer discussed the SLMPD’s and the International Association of Chiefs of Police’s (IACP) standards for pepper spray and opines that Detective Vaughan’s use of pepper spray did not comply with those standards. SLMPD and IACP standards are not common knowledge for jurors, and Meyer’s testimony will help contextualize the evidence the jury will hear about Detective Vaughan’s use of pepper spray.

    Although Meyer’s report also states that Detective Wentzel’s “alleged tackling [of] Plaintiff to the street[] did not conform with SLMPD policy or contemporary law enforcement training or procedures,” the Court held that Meyer does not provide similar insight into accepted police procedure for that kind of force.

    Held

    The Court granted in part the Defendants’ motion to exclude Plaintiff’s expert, Greg Meyer.

    Key Takeaway:

    If Meyer had relied on SLMPD or IACP standards for uses of force like Wentzel’s, or explained why, based on his own extensive law enforcement experience, he believes Wentzel could have used less force to control Rev. Gray, the opinion might be admissible. But without that information, the Court cannot properly assess whether the opinion satisfies Rule 702‘s requirements.

    Case Details:

    Case Caption: Gray V. City Of Saint Louis, Missouri Et Al
    Docket Number: 4:18cv1678
    Court Name: United States District Court, Missouri Eastern
    Order Date: March 31, 2025
  • Law Enforcement Expert Witness’ Report Criticizing the Actions of SPD Deemed Conclusory

    Law Enforcement Expert Witness’ Report Criticizing the Actions of SPD Deemed Conclusory

    A district judge in Washington refused to admit the Law Enforcement Expert Witness’ testimony with regard to the claims of outrage, negligence and assault filed against the Seattle Police Department.

    On May 30, 2020, organizers planned two demonstrations in downtown Seattle to protest the May 25, 2020 killing of George Floyd in Minneapolis: (1) “The March for George Floyd,” scheduled from 12:00 p.m. to 6:00 p.m. on Fifth Avenue, and (2) “The Defiant Walk of Resistance Against Injustice,” scheduled to begin at 3:00 p.m. and to go from Westlake Park to the federal courthouse at Seventh Avenue and Stewart Street. Sergeant Sean Moore served as the leader of Platoon 1’s West Bikes #3 at The Defiant Walk of Resistance Against Injustice. 

    After learning about the demonstrations through his parents or his church, Avery decided to attend the events along with his young son J.A., other family members, and church members.

    Plaintiffs Are Injured During the May 30, 2020 Demonstrations

    An escalation between officers and demonstrators ensued after the arrest of one of the demonstrators. Several demonstrators, including two female demonstrators (one wearing a black sweatshirt and one wearing a white t-shirt and bike helmet), moved toward the police line. At one point, Officer Moore ran up to the line from behind and repeatedly yelled “Move back!” with a blast ball in his left hand and OC spray in his right hand. The female demonstrator wearing the bike helmet then shouted “You move back!” while pushing over the line, grabbing an officer’s baton, and pushing back against him.

    At the beginning of this disturbance, Avery moved quickly to his left towards the disturbance, holding J.A. to his right side and approaching until he was immediately behind the female demonstrator. Then, without verbal warning, Officer Moore deployed OC spray in the direction of this demonstrator.

    When Officer Moore deployed the OC spray at the female demonstrator in the bike helmet, Avery had his left arm around her waist as she turned away from the spray, exposing his left side to Officer Moore’s deployment. Avery had his right arm around J.A., who stood behind his father and the female demonstrator. As Avery and J.A. retreated from the altercation, Avery placed his left hand on or near J.A.’s face and kept his arms around him as they walked away. Moments later, J.A. began reacting to the OC spray’s painful effects and received assistance from other demonstrators.

    Motion to exclude

    Avery initiated this action in April 2022, raising claims for violations of the Washington Law Against Discrimination, outrage, negligence, assault, and constitutional violations under 42 U.S.C. § 1983.

    The City moved to exclude the testimony of Plaintiffs’ law enforcement expert, Russ Hicks, because his report consisted of opinions which were “improper legal conclusions and lacked any expert analysis that might be helpful to a jury.”

    Law Enforcement Expert Witness

    Russ Hicks is a retired, 30-year law enforcement officer and former police academy supervisor and trainer. He was a commissioned police officer from 1991-2016. He was also an instructor at the Washington State Criminal Justice Training Commission (WSCJTC) from 2007-2021.

    Discover more cases with Russ Hicks as an expert witness by ordering his comprehensive Expert Witness Profile report.

    Discussion by the Court

    Many of Hicks’ Opinions Consisted of Legal Conclusions

    The Court agreed with the City when it contended that many of Hicks’ opinions consisted of legal conclusions. For instance, Hicks repeatedly characterized the actions of Seattle Police Department “SPD” as “negligent,” concluded that Officer Moore’s use of force was “excessive,” and stated that Plaintiffs “were seized” by Officer Moore’s use of force. The Court held that almost all of Hicks’ opinions are supported by nothing more than conclusory statements. 

    Hicks’ Opinions Were Mostly Unsupported

    Hicks speculated that it is more likely than not that if Officer Moore had provided a warning about the pepper spray, she would have let go of the baton and Sgt. Moore wouldn’t have deployed this MK-9 pepper spray. The Court held that Hicks provided no support whatsoever for this opinion, rendering it unreliable. He did not explain how his experience led to the conclusion reached.

    As for Hicks’ opinion that SPD’s failure to “provide or call for aid for Avery and his 7-year-old son” was contrary  to law, training, and policy, the Court held that it did not offer any specialized knowledge and in fact contradicted the video evidence. He asserted that the alleged failure to aid was contrary to training, explaining only that officers “are provided with instruction on providing first aid to subjects injured by law enforcement” at WSCJTC training. The Court held that he did not explain how such training bears on the facts at issue beyond the suggestion that officers knew how to administer first aid.

    The Court found Hicks’ opinion that “Officer Moore deviated from SPD policy regarding providing warnings in advance of deploying pepper spray despite having enough time to give a warning” similarly unsupported because untrained layman would be qualified to determine that issue.

    Finally, Hicks opined that Officer Moore should have used the MK-4 pepper spray instead of the MK-9 because “it is possible that the smaller dispersal area [of the MK-4] would have satisfied the immediate safety goal.” The Court, once again, held that Hicks failed to “back up his opinion with specific facts.”

    Held

    The Court granted the City’s motion to exclude the testimony of Plaintiffs’ law enforcement expert, Russ Hicks.

    Key Takeaway:

    The Court held that almost all of Hicks’ opinions were supported by nothing more than conclusory statements. Conclusory assertions like those contained in Hicks’ report would not assist the trier of fact to understand the evidence.

    Nothing in either Daubert or Rule 702 requires the district court to admit opinion evidence that is connected to existing data only by the ipse dixit of the expert.

    Case Details:

    Case Caption: Avery V. City Of Seattle Et Al
    Docket Number: 2:22cv560
    Court: United States District Court, Washington Western
    Order Date: June 12, 2024