Emergency Terry Stops: Seventh Circuit Affirms Officers’ Authority to Briefly Detain Apparent Hostages to Identify, Assess Firearms Risk, and Prevent Interference

Introduction

In Ryan Moderson v. City of Neenah, the United States Court of Appeals for the Seventh Circuit addressed whether police officers violated the Fourth Amendment when they briefly detained individuals who had fled a chaotic and still-unfolding hostage situation inside a motorcycle shop. The plaintiffs—three hostages who were detained after escaping—sued the City of Neenah and individual officers, alleging unreasonable seizures under the Fourth Amendment. They also challenged the dismissal of Sergeant Angela Eichmann and argued that qualified immunity should not protect the officers.

Writing for a panel that included Judges Easterbrook, Rovner, and Jackson-Akiwumi (author), the court affirmed summary judgment for the officers. The opinion clarifies that, in inherently dangerous and fluid emergencies like an ongoing hostage scenario, officers may conduct brief investigatory detentions—even of apparent hostages—to serve a focused mission: (1) ascertain identities of individuals exiting the scene, (2) determine whether those individuals possess firearms and how many, and (3) investigate without interference. The court also underscores the importance of properly developing Terry-stop arguments on appeal and reiterates that Section 1983 liability hinges on personal involvement, not supervisory status alone.

Summary of the Opinion

The Seventh Circuit affirmed the district court’s grant of summary judgment to the officers and the dismissal of Sergeant Angela Eichmann. Key holdings include:

The court assumed—without deciding—that the plaintiffs’ detentions were Terry stops. Given the heavy gunfire, smoke, confusion about the number of shooters, and noncompliance inside the shop, the officers reasonably suspected an ambush and acted within the bounds of the Fourth Amendment by briefly detaining those exiting the building. The seizures were reasonable at inception.
The scope and duration of the detentions were tied to the officers’ mission in the emergency: identity verification, assessment of firearms risk, and preventing interference with the active scene. For plaintiff Ryan Moderson, the detention ended when he was reunited with his son; his later interactions at the station were consensual.
As to plaintiffs Michael Petersen and Steven Erato, the court did not resolve whether their detentions evolved into arrests or whether steps such as handcuffing and transport to the station were necessary, because the plaintiffs’ appellate briefing was underdeveloped and did not squarely engage Terry principles. Those claims were therefore waived.
Sergeant Eichmann was properly dismissed because plaintiffs failed to adduce evidence of her personal involvement in the alleged Fourth Amendment violations. Her brief field interaction with a non-party and conjecture about her supervisory role were insufficient.
Because no constitutional violation was found, the court did not reach qualified immunity, and plaintiffs’ punitive damages claim necessarily failed.

Analysis

Precedents Cited and How They Informed the Decision

Terry v. Ohio, 392 U.S. 1 (1968): The foundational case for investigatory stops. The court assumed the detentions were Terry stops and applied Terry’s framework—asking whether the stops were justified at inception and reasonable in scope and duration. The opinion also reiterates the familiar proposition that probable cause is required only when a stop morphs into an arrest.
United States v. Arvizu, 534 U.S. 266 (2002): Reinforces that brief investigatory stops for suspected criminal activity are within Fourth Amendment protections and must be assessed under the totality of the circumstances. This totality-driven approach is critical in volatile, rapidly changing emergencies.
United States v. Mendenhall, 446 U.S. 544 (1980), and United States v. Lopez, 907 F.3d 472 (7th Cir. 2018): Provide the touchstone for when an encounter becomes a seizure, i.e., whether a reasonable person would feel free to terminate the encounter. These principles guided the court’s conclusion that Ryan Moderson’s subsequent station visit was consensual.
United States v. Olson, 41 F.4th 792 (7th Cir. 2022), and Matz v. Klotka, 769 F.3d 517 (7th Cir. 2014): Confirm that probable cause is required when an investigative detention becomes an arrest and that the detention’s scope must be reasonably related to the justification for the interference.
United States v. Howell, 958 F.3d 589 (7th Cir. 2020): Emphasizes that the officer’s experience and the totality of the circumstances inform reasonable suspicion—key in evaluating officers’ split-second decisions during a possible ambush.
United States v. Williams, 731 F.3d 678 (7th Cir. 2013): The court cited Williams to stress that officers need not “bet their lives” on initial dispatch descriptions when on-the-ground facts diverge; they may act on the realities they confront.
Estate of Biegert v. Molitor, 968 F.3d 693 (7th Cir. 2020): Supports the proposition that restraining individuals can be appropriate in “inherently dangerous situations,” even without suspicion of a crime. This authority is pivotal in legitimizing the temporary detention of apparent hostages during a dynamic, violent event.
Illinois v. Caballes, 543 U.S. 405 (2005), and United States v. Howard, 729 F.3d 655 (7th Cir. 2013): Caballes explains that a lawful stop becomes unlawful if prolonged beyond its mission; Howard frames the reasonableness balance between marginal intrusion and the governmental interest in safe, interference-free investigation.
United States v. Bullock, 632 F.3d 1004 (7th Cir. 2011): Acknowledges that in some circumstances, handcuffing and other force typically associated with arrest can be reasonable within a Terry stop. The court referenced Bullock while expressly declining to decide whether such measures were necessary for Petersen or Erato, given the plaintiffs’ briefing deficiencies.
Summary judgment and appellate preservation authorities: Anderson v. Liberty Lobby, 477 U.S. 242 (1986) (de novo review; reasonable jury standard); Smith v. Finkley, 10 F.4th 725 (7th Cir. 2021) (facts viewed in light most favorable to non-movant); Madero v. McGuinness, 97 F.4th 516 (7th Cir. 2024) (reversal standard). Waiver/forfeiture for underdeveloped arguments: Brockett v. Effingham County, 116 F.4th 680 (7th Cir. 2024); United States v. Valenzuela, 931 F.3d 605 (7th Cir. 2019); United States v. Berkowitz, 927 F.2d 1376 (7th Cir. 1991); United States v. Dunkel, 927 F.2d 955 (7th Cir. 1991).
Qualified immunity shortcut: Hicks v. Illinois Department of Corrections, 109 F.4th 895 (7th Cir. 2024) (no need to reach qualified immunity if there is no underlying constitutional violation).

Legal Reasoning

The opinion proceeds in two steps. First, it assesses whether the detentions were justified at inception. Second, it evaluates whether their scope and duration remained reasonably related to the officers’ mission in context.

On the first step, the court assumed the detentions were Terry stops and concluded they were justified at inception. Dispatch reported a long-haired, bearded man with a MAC-10 submachine gun holding hostages and threatening imminent execution. When officers breached the premises, they encountered heavy smoke, gunfire striking an officer’s helmet, and apparent noncompliance, with movements suggesting a potential flanking maneuver. Officers reasonably feared multiple shooters and an ambush. The court emphasized, citing Williams, that officers were not required to “bet their lives” on initial reports of a lone gunman that the unfolding facts contradicted.

Critically, the court grounded the propriety of stopping escaping hostages in Estate of Biegert: in inherently dangerous situations, officers may restrain individuals—even absent individualized suspicion of crime—to protect safety and control the scene. The temporary detentions of people exiting the building were thus lawful at inception.

On the second step—scope and duration—the court framed the officers’ mission for the emergency investigatory stops as threefold:

Ascertain the identities of people leaving the scene before they disappeared;
Determine whether anyone possessed firearms and, if so, how many;
Continue investigating without interference from those detained.

With this mission in view, the court analyzed each plaintiff:

Ryan Moderson: Handcuffed upon exit, questioned briefly, then transported to reunite with his son, after which he voluntarily proceeded to provide a written statement. The court held the detention lasted no longer than necessary to dispel suspicion that he might be a shooter and to serve the mission. His subsequent stationhouse interaction was a consensual encounter, as nothing suggested he did not feel free to decline—tracking Mendenhall and Lopez.
Michael Petersen and Steven Erato: The court assumed they were seized and recognized more intrusive measures occurred (handcuffing, transport, property taken, interviews). But the court expressly declined to decide whether those steps were necessary to the mission or whether the detentions escalated into arrests requiring probable cause. The reason: plaintiffs’ arguments were “skeletal,” failed to engage Terry or the stop-versus-arrest distinction, and they filed no reply brief to answer the officers’ detailed Terry arguments. Under Brockett, Valenzuela, Berkowitz, and Dunkel, those underdeveloped claims were waived.

Given its merits ruling that no Fourth Amendment violation occurred, the court did not reach punitive damages or qualified immunity (Hicks).

As to Sergeant Eichmann, the court affirmed her dismissal for lack of personal involvement. Section 1983 liability requires that a defendant cause or participate in the alleged deprivation; a supervisory or “in charge of the operation” theory, without evidence of causation, is insufficient. Eichmann’s brief questioning of a non-party and the unsubstantiated “information chain” theory did not link her to any plaintiff’s detention, warranting dismissal.

Impact and Forward-Looking Implications

This decision meaningfully reinforces several principles in Fourth Amendment practice, particularly in high-risk, fluid emergency responses:

Emergency Terry stops for non-suspects: The court expressly endorses a safety-centered rationale that permits officers to briefly detain even apparent victims or witnesses during unfolding violence, consistent with Estate of Biegert. The articulated three-part mission—identification, firearms assessment, and interference prevention—offers concrete guidance to agencies on what objectives can justify the scope and duration of such stops.
Officer-safety deference in chaotic scenes: By emphasizing that officers need not rely on initial dispatch descriptions when on-the-ground facts suggest greater danger, the court gives operational latitude for split-second judgments where the number of shooters is unknown and gunfire continues. Expect this language to be cited in future active-shooter and mass-casualty litigation.
Intrusive measures within Terry: Although the court did not decide whether handcuffing and station transport were justified for Petersen and Erato, it reiterated the Bullock principle that such measures can be consistent with a Terry stop in some scenarios. Departments should still train to document why more intrusive measures are necessary to serve the mission and to transition to arrest or release promptly as facts develop.
Appellate preservation: Plaintiffs’ failure to frame their claims in Terry terms—and to grapple with stop-versus-arrest doctrine—proved fatal. The opinion signals that appellate courts expect robust development of Fourth Amendment theories; skeletal assertions will be deemed waived even in high-stakes civil rights cases.
Personal involvement in Section 1983: The dismissal of Sergeant Eichmann underscores a familiar but often overlooked rule: supervisory status and generalized responsibility do not create liability absent evidence of causal participation in the specific constitutional violation.
Qualified immunity not reached: Because the court resolved the case on the merits, the qualified immunity landscape for similar scenarios remains formally unchanged. But the merits holding itself—validating emergency detentions of apparent hostages to serve the three mission objectives—will likely inform the “clearly established law” analysis in future cases.

Unresolved questions remain. The court avoided deciding whether transporting an apparent hostage to a stationhouse during an ongoing emergency is consistent with Terry without probable cause. Future litigation will likely test the outer limits of emergency stop duration, geographic relocation, and property retention (e.g., phones, keys) absent consent or probable cause, now with the Seventh Circuit’s mission framework as a guidepost.

Complex Concepts Simplified

Seizure: A person is “seized” when, under the circumstances, a reasonable person would not feel free to end the encounter and walk away.
Terry stop (investigatory detention): A brief detention based on reasonable suspicion of criminal activity (less than probable cause). It must be narrowly tailored in scope and duration to its investigative mission.
Arrest: A more significant restraint on liberty that requires probable cause. A stop that becomes too prolonged or too intrusive for its mission can turn into an arrest.
Scope and duration: Even a justified stop becomes unlawful if it lasts longer than necessary or strays from its mission (for example, detaining someone longer than needed to identify them and neutralize safety risks).
Inherently dangerous situations: High-risk scenarios (like active hostage or active-shooter events) where officers may briefly restrain people for safety and scene control even if those people are not suspected of a crime.
Consensual encounter: Interactions where a reasonable person would feel free to decline or terminate the engagement. No Fourth Amendment seizure occurs in such encounters.
Personal involvement (Section 1983): Liability requires that the defendant personally caused or participated in the constitutional violation; supervisory status alone is not enough.
Qualified immunity: Shields officials from liability unless they violated a constitutional right that was clearly established at the time. Courts often bypass this analysis if they find no constitutional violation.
Waiver/forfeiture on appeal: Arguments must be adequately developed with supporting authority. Bare assertions or failure to engage opposing arguments can forfeit claims on appeal.

Conclusion

Ryan Moderson v. City of Neenah is a significant Seventh Circuit decision clarifying that in ongoing, violent emergencies, officers may conduct Terry-style detentions of even apparent hostages to identify them, assess immediate firearms risks, and prevent interference with the unfolding investigation. The court’s three-part mission framework provides practical guidance for law enforcement and a measuring stick for subsequent judicial review.

Equally important are its procedural and doctrinal reinforcements: (1) appellate courts will deem underdeveloped Fourth Amendment arguments waived; (2) intrusive measures like handcuffs can, in some circumstances, remain within the Terry ambit, though transporting to a stationhouse remains a fact-intensive question; and (3) Section 1983 liability turns on personal involvement, not general supervisory responsibility. By affirming on the merits and declining to reach qualified immunity, the court strengthens a safety-first approach in exigent circumstances while reminding litigants that precise, fully developed arguments are indispensable to prevail on appeal.