Petitioners have argued that the use of crowd-control weapons may be seen as retaliation against the exercise of freedom of speech or assembly.

The First Amendment is also implicated when law enforcement actions create a “chilling effect” in which protesters and journalists become afraid to exercise their First Amendment rights due to credible threats of retaliation.

Successful claims must show that retaliatory animus or intent directly resulted in the injury of a person engaged in a protected activity.

Opinions have established that crowd-control weapons misuse can, at least circumstantially, suggest retaliatory intent.

Index Newspapers LLC v. U.S. Marshals Service (2020): crowd-control weapons misuse, including shots at the head and direct fire of tear gas canisters and pepperballs, can constitute circumstantial evidence of retaliation.

Los Angeles Press Club v. Noem (2026): The Ninth Circuit agreed with a District Court ruling that direct fire and shots to the head raise an inference of retaliation.

For journalists, First Amendment cases focus almost exclusively on allegations of retaliatory intent, which crowd-control weapons misuse can help establish.

Petitioners have argued that excessive force (such as law enforcement violence against protesters) can constitute an unreasonable seizure.

Use of force must be objectively reasonable (Graham v. Connor).

The standard asks whether a reasonable officer would act similarly under the same circumstances. To determine this, courts look at the totality of the circumstances, meaning they consider all the factors leading up to and including the use of force by an officer. (Barnes v. Felix).

Defendants have argued that crowd dispersal does not constitute a “seizure,” but several courts have affirmed that force severe enough to incapacitate an individual, restraining movement just as an arrest would, falls under the Fourth Amendment.

Chicago Headline Club v. Noem (2025): Crowd dispersal alone may not constitute seizure, but the District Court found that targeting body parts where only deadly force would be permitted (e.g., the head) shows intent to incapacitate and restrain, constituting seizure.

Cheairs v. City of Seattle (2025): Close-range stun grenade detonations can constitute an incapacitating seizure.

Sanderlin v. Dwyer (2024): Shots to the groin can constitute an incapacitating seizure.

Nelson v. City of Davis (2012): Shots to the head can constitute an incapacitating seizure.

The term “misuse” as defined in this study does not neatly fit into the Fourth Amendment test. The Fourth Amendment may be implicated where the misuse of a weapon in a manner that violates the standards of law enforcement’s use of force policy or the manufacturer’s standard would be compelling evidence that the actions of an officer are not “objectively reasonable.”

Therefore, many of the incidents described may be unreasonable and thus be categorized as excessive use of force.

Plaintiffs have argued that the use of crowd-control weapons violates the due process clause by infringing on their right to bodily integrity.

Excessive force may instead be evaluated as a due process question.

Note: While many cases related to the use of crowd-control weapons at protests invoke the Fourth Amendment, some also include claims of substantive due process violation.

The test asks whether the conduct shocks the contemporary conscience or constitutes conduct intended to injure in a manner that is unjustifiable by any government interest (County of Sacramento v. Lewis).

Harming individuals, particularly vulnerable groups like children or pregnant individuals, may violate due process if law enforcement actions shock the conscience of the judge, jury, or other finders of fact.

Chicago Headline Club v. Noem (2025): District Court identified close-range use of impact projectiles and the use of chemical irritants against vulnerable populations (e.g., pregnant individuals, children, and babies) as conscience-shocking behaviors that potentially violate the right to substantive due process.

Several of our categories of misuse are directly informative for the shocks-the-conscience test, particularly close-range impact projectile use, and indiscriminate chemical agent deployment near vulnerable people.

Law enforcement has a duty of care to the community. Therefore, violations can be considered torts, especially negligence (as opposed to crimes) in the face of foreseeable injury.

Because Daniels v. Williams established that negligent acts by state officials do not violate constitutional due process, claims against federal officials for negligence must proceed under the FTCA.

Labella v. United States (2024): A plaintiff, featured in PHR's 2020 study Shot in the Head, was shot in the forehead with a kinetic impact projectile by a deputy U.S. Marshal outside the federal courthouse in Portland. He filed suit for negligence, battery, and intentional infliction of emotional distress, all torts under the FTCA. The case settled out of court with the Department of Justice.

Some individuals identified in our study have declared intent to file claims under the FTCA.