Law Enforcement Experts Not Allowed to Opine on Sound Professional Standards

Plaintiff Robert Dale filed this action alleging that Corporal Daniel Gerlitz and Officer Michael Merucci unlawfully arrested him without probable cause, used excessive force, and failed to intervene to stop the unconstitutional conduct, in violation of the Fourth Amendment after Dale’s teen daughter, Isabella, dropped her phone and accidentally dialed 911.

The Plaintiff filed a motion asking the Court to exclude the opinion of defense expert Victor Wahl while the Defendants filed a motion to exclude testimony from the Plaintiff's expert, Scott J. Hilden.

Law Enforcement Expert Witnesses

Victor Wahl is a retired law enforcement officer with thirty years of experience at the City of Madison Police Department ("MPD"). Wahl has a B.A. in sociology and a J.D. from the University of Wisconsin. Wahl had many training and leadership roles while at the MPD, including as Acting Chief of Police, Assistant Chief of Police, pre-service academy instructor, lead instructor for impact projectile, overseer of the taser program and lieutenant of MPD's Professional Standards & Internal Affairs. Wahl currently serves as a senior advisor for the Center for Naval Analyses Institute for Public Research, works for the Center for Justice Research and Innovation and is a member of the Police Executive Research Forum (PERF) and the International Association of Chiefs of Police (IACP).

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

Scott J. Hilden is a seasoned law enforcement professional. In addition to holding a B.A. in criminal justice from Michigan State University and a master of liberal studies from Eastern Michigan University, Hilden has served in high-level roles in several municipal law enforcement entities in Michigan over his thirty-three-year career. Hilden asserts that he is a member of several law enforcement groups and has extensive experience and training in "Arrest and Detention," "Use of Force/Defensive Tactics," "Training," "Police and Procedures" and "Management and Supervision." Hilden stated that he has provided expert testimony in three other federal cases over the past two years.

Gain a comprehensive understanding of Scott Hilden’s qualifications and casework history with his Expert Witness Profile report.

Discussion by the Court

A. Victor Wahl

Wahl stated that he relied on the evidence available in the case to come to his opinions. His report opined on reasonable suspicion, probable cause, the emergency doctrine and use of force. Wahl relied on the Wisconsin Department of Justice Law Enforcement Standards Board's Defensive and Arrest Tactics (DAAT) training system, Wisconsin court cases, Wisconsin Department of Justice Law Enforcement Standards Board's guide on Constitutional Law and his own experience on what officers are "generally trained on" to come to his conclusions.

The Plaintiff argued that these opinions are legal conclusions on ultimate issues of the case. He contended that whether the officers had reasonable suspicion or probable cause is outcome determinative for his claims and "are necessary elements of [the Plaintiff's] allegations that Defendants violated his Fourth Amendment rights."

1. Analysis of Wahl's Testimony

The Plaintiff asked the Court to consider whether the information on pages 6-9 of Wahl's report constitutes testimony as to legal conclusions that will determine the outcome of the case, or whether the information equates to Wahl attempting to usurp the Court's role in instructing the jury on the applicable legal principles. The Court agreed that the three opinions the Plaintiff contests—and the surrounding information on pages 6 through 9 of the report—state conclusions of law.

Opinion 1 appears in the section of Wahl's report titled "Reasonable Suspicion." Wahl begins this section with his opinion, stating "at the time that the Plaintiff attempted to flee into his apartment, a reasonable officer would conclude that reasonable suspicion existed to detain the Plaintiff." Only after stating that conclusion does Wahl attempt to explain the professional standards upon which he relies to draw it.

The section of Wahl's report titled "Probable Cause" begins the same way; this is where the Plaintiff got Opinion 2. Wahl concluded that "a reasonable officer would also conclude that probable cause existed to arrest the Plaintiff for disorderly conduct at that point." Wahl then defines and analyzes Wisconsin's disorderly conduct statute and concludes that the officers had probable cause to arrest the Plaintiff. He does the same in the "Emergency Doctrine" section of the report (Opinion 3). For both, and without citing any training or standards, he opined on what officers are "generally trained on" regarding 911 calls.

Pages 6 though 9 of the report are rife with attempts to instruct the jury on the law and to make other legal conclusions. On those pages, Wahl either is making a legal conclusion or attempting to instruct the jury on the law. Wahl twice defines reasonable suspicion and describes the facts of the case that, to him, "were clearly suspicious circumstances." He cloaks his legal instructions with the phrase "officers are generally trained that," but still he offers his own definitions of legal concepts with citations to Wisconsin case law. And he does not explain where the "general training" comes from.

There is ample ground to exclude pages six through nine of Wahl's report on the grounds that the opinions he provides are legal conclusions, attempts to instruct the jury on the law and lack any citation of relevant police training or standards.

The Plaintiff has not asked the Court to exclude any of the portions of Wahl's report relating to the Plaintiff's excessive force claim. But in its gatekeeper role, the Court has concerns about some of those. The first page of Wahl's "Use of Force" section—the balance of page 9 of his report—is the most problematic. He drops any pretense that he is explaining what "officers are generally trained on" and baldly explains his view of the law.

The rest of Wahl's report—pages 10 through 16—lays out the Wisconsin Department of Justice Law Enforcement Standards DAAT training system and de-escalation and applies it to the officers' conduct. Even this section contains legal conclusion. He instructs on the constitutional "objective reasonableness" standard for analyzing excessive force claims, then opines that the DAAT system "provides a framework to help officers make use of force decisions and to analyze the reasonableness of those decisions." He states that "Gerlitz and Merucci had clear legal authority to control [the Plaintiff] during this encounter."

Beyond these concerns, as the Court will explain in more detail below, it is not clear how Wahl's testimony about the DAAT manual would assist the trier of fact in determining whether the Defendants' conduct met the objective reasonableness standard—whether they used more force than was reasonably necessary to effectuate the seizure of the Plaintiff.

B. Scott Hilden

Hilden explained that in coming to his conclusions, he relied on practices, policies and standards established by "organizations like" the International Association of Chiefs of Police ("IACP"), the Commission on Accreditation for Law Enforcement Agencies ("CALEA") and the Police Executive Research Forum ("PERF"). Hilden stated that he "evaluated whether the officers had lawful justification for the arrest" and "examined whether the officers' actions were reasonable, necessary, and proportional to [the Plaintiff's] conduct." Hilden asserted that although he uses legal terms, "any final determinations remain the responsibility of the court and fact-finders."

The Defendants argued that several of these opinions verge on conclusions of law. They contended that much of Hilden's "report contains final conclusions, phrases, and thoughts about illegal or unlawful conduct."

1. Analysis of Hilden's Testimony

Opinion 1

Starting with the portions of Hilden's testimony that the Defendants argue are legal conclusions, in "Opinion 1" of his report, Hilden applied the Cudahy Police Department's Use of Force Policy and the IACP's model policy to the facts of the case and concludes that the officers' conduct departed from those standards. This section contains several potentially problematic statements. In the first paragraph, Hilden writes, "the officers' initial seizure of [the Plaintiff] did not follow law enforcement protocols of establishing the reasonable suspicion required by law." This statement skirts dangerously close to concluding that the officers did not have reasonable suspicion. Later on, Hilden refers to Opinion 1 as establishing that "the officers' initial seizure of [the Plaintiff] was not supported by reasonable suspicion."

Hilden concluded that the seizure was "unlawful" because it lacked the "reasonable suspicion required by the Constitution." He again refers to the arrest as "unlawful" when he asserts that it "tainted every subsequent action the officers took." These are legal conclusions and verge on instructing the jury on the law.

Opinion 2

Hilden's next opinion, "Opinion 2," analyzes police standards, save for one line. Hilden asserted that "the officers' decision to force their way into [the plaintiff's] residence represented a significant deviation from the law and widely accepted police practices and training regarding warrantless entries." Hilden's assertion that the officers' decision "represented a significant deviation from the law" verges on a legal conclusion. Aside from that sentence, Hilden lays out the relevant police training and standards and identifies ways in which the officers' conduct did not align with it.

Opinion 6

For the Opinion 6 (the last specific opinion that the Defendants argue contains legal conclusions), Hilden offers a number of "alternative options" to many of the officers' actions. Hilden asserted that the officers had "safer, more professional, and constitutionally appropriate options available" and said that "repeated failure to use these options shows a clear deviation from the law and accepted police practices and training."

Hilden offered four alternative actions. He contended that at the initial contact with the Plaintiff the officers could have de-escalated and communicated with the plaintiff instead of intensifying the situation.Hilden opined that instead of physically arresting the plaintiff, the officers could have continued to investigate the situation. Likewise, Hilden stated that the officers could have avoided a physical confrontation by deescalating and reassessing "alternative options." Finally, Hilden asserted that the officers' use of force "was inconsistent with their training" and that they "had a clear set of alternatives they failed to employ." Those alternatives are: "De-escalation and Verbal Commands"; "Empty-Hand Control Techniques"; and "Intermediate Weapon (Taser)."

Hilden's alternatives are not legal conclusions, but his contentions about what is "constitutionally appropriate" and how the officers' failure to follow the alternatives "shows a clear deviation from the law" cross the line into legal conclusions. These statements amount to telling the jury that the officers are liable to the Plaintiff.

The Defendants contended that "bedrock principles in use of force law include the fact officers are not required to engage in alternative measures or lesser degrees of force, and Wisconsin officers under Wisconsin Department of Justice Law Enforcement Standards Board's Defensive and Arrest Tactics (DAAT) are taught as much." The Defendants do not cite a source for this "bedrock principal;" even if they had, Hilden does not assert that officers must engage in alternatives measures at the outset, but rather that, judged after the fact, the alternatives illustrate the alleged unreasonableness of the officers' conduct.

Opinion 5

Although the Defendants did not identify them in their written brief, there are other portions of Hilden's testimony that are problematic. In Opinion 5, Hilden opined that the charges of "Resisting an Officer and Disorderly Conduct filed against [the Plaintiff] are not supported by the facts reported by the officers themselves." Hilden stated that "under Wisconsin law, a key element of this offense is that the officer must be acting with lawful authority." He reiterates from Opinion 1 that the officers did not have reasonable suspicion to seize the plaintiff and concludes that "therefore, any subsequent commands related to that seizure would not be considered lawful." This is a legal conclusion about the existence, or lack thereof, of reasonable suspicion mixed with an instruction on the law used to conclude that the plaintiff could not have been guilty of resisting an officer, but it is irrelevant. At the May 2026 hearing, the Court was unaware of the false arrest claim, and so concluded that this opinion was irrelevant to the excessive force claim. Reviewing it now, with the understanding that the Plaintiff's first claim is a false arrest claim, the Court concluded that it is a legal conclusion. As part of his opinion on disorderly conduct, Hilden states that disorderly conduct "typically requires conduct that causes a public disturbance." This is an instruction on the law and thus usurps the function of the Court.

Opinion 3

As for the Defendants' credibility argument, Hilden made the following statement in Opinion 3:

In response to this non-assaultive resistance, Gerlitz stated the subsequent strike was not aimed at its eventual point of impact, stating,

"This was not the intended target. I was intending to hit the upper torso area, not his face."

The jury will determine if his claim that the head was not his intended target is credible. Still, from an instructor's perspective, an elbow strike from a top position is a powerful and committed gross motor skill. To suggest a trained officer would "accidentally" deliver such a blow to the head defies the core principles of targeting and body mechanics.

The Defendants argued that the Court should exclude this statement because at bottom, it constitutes a credibility determination and thus invades the province of the jury. The Defendants are correct; as Hilden himself concedes, witness credibility is the province of the jury.

Hilden's opinion crosses the line into his making a credibility determination, something he seems to acknowledge with his statement that the jury will make the credibility determination. His opinion is tantamount to telling the jury that they cannot believe Gerlitz's testimony.

The Defendants made a global argument that any time Hilden uses a non-DAAT or non-Wisconsin source for judging use of force or any other opinion, he made a legal conclusion. The Court disagreed.

The Defendants' qualified immunity argument is particularly perplexing. The Defendants have cited no authority for the proposition that a Court should exclude expert witness testimony because it might have some collateral impact on another issue. And here, the question of whether the officers followed IACP, CALEA or PERF policy is only tangentially relevant to the question of whether the officers had probable cause to arrest the Plaintiff, or whether the amount of force they used was objectively reasonable.

C. Helpfulness to the Jury

The Court agreed with the parties that both experts offer legal conclusions and instructions on the law for both the false arrest claim and the excessive force claim. Indeed, both parties' experts are guilty of doing what the parties accuse their opponent's expert of doing. Both parties loudly object to the other's expert stating opinions or conclusions about whether there was or was not reasonable suspicion, probable cause and objectively reasonable use of force. Both object to the other's expert characterizing actions as legal or illegal, constitutional or unconstitutional. All the while, their own experts are doing the very thing to which they object. But the parties' insistence that each needs to call an expert witness to explain police training and procedures to the jury begs the question of how the testimony the experts offer would be helpful to a jury—a question the court may address sua sponte.

The Court will exclude both experts in their entirety, but will do so without prejudice. Once the Court has ruled, the parties may ask the Court to reconsider its ruling excluding the two experts, as long as the parties first meet and confer to come to some agreement about the topics on which the experts will provide testimony. If the parties seek reconsideration, the Court will expect them to provide a detailed explanation of why expert testimony about police procedure is relevant or necessary in the context of the facts alleged here.

Held

• The Court granted the Plaintiff's motion to exclude Victor Wahl's testimony.

• The Court granted the Defendants' motion to exclude Scott Hilden's testimony.

Key Takeaway

Experts cannot testify as to legal conclusions that will determine the outcome of the case. That said, an opinion is not automatically inadmissible just because it embraces an ultimate issue to be decided by the trier of fact.

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