Article written by Attorney Timothy Mainella
As seen in the Spring 2026 Issue of New Hampshire Trial Lawyers Quarterly
“Monell is a case about responsibility.” Pembaur v. City of Cincinnati, 475 U.S. 469, 478, (1986).
When a group of municipal actors conspire, work together, or collectively fail to prevent the deprivation of an individual’s civil rights – when, say, multiple officers beat a suspect, and all work together to cover it up by failing to report any use of force – it stands to reason that their employer may bear some responsibility. After all, how could such a situation occur if the actors involved were not encouraged, or at least emboldened, tacitly or otherwise, by a policy or custom attributable to the municipality?
The elements a plaintiff must prove to succeed on a Monell claim – a 42 U.S.C. § 1983 action based upon an unconstitutional municipal policy or custom — are deceptively simple: the policy or custom must be attributable to the municipality, and the policy or custom must have been the cause of and the “moving force” behind the depravation of the plaintiff’s rights.
Attributing a policy or custom to a municipality is traditionally difficult work. Typically, courts require evidence of repeated misconduct by municipal employees or deliberate indifference to such conduct to establish municipal liability.
But what about the case where a group of officers beat a suspect together, and then together conspire to cover it up? What about a case where a constitutional violation occurs, and a number of municipal actors are involved in the violation or are in position to prevent it, but nobody does anything at all, during or after?
There is a series of cases in the First Circuit which show that a plaintiff may be able to succeed on a “unanimity of action” theory – that a plaintiff may be able to show that the concerted action of a number of actors is evidence itself of a policy or custom so widespread as to have the force of law. This evidence, of course, is best used in concert with evidence showing repeated violations, deliberate indifference, ratification, or training or supervision failures; the more that can be alleged, the better.
In Bordanaro v. McLeod, the First Circuit described this theory:
“Additional support for the existence of such a practice can be inferred from the event itself. This incident involved the joint actions of the entire night watch of the Everett Police Department. A reasonable inference to draw from this is that all of the officers involved were operating under a shared set of rules and customs. The fact that all of these officers acted in concert is further evidence that there was a pre-existing practice of breaking down doors when apprehending felons. Absent such a norm, it is highly unlikely such unanimity of action could occur. While it is true that evidence of a single event alone cannot establish a municipal custom or policy, where other evidence of the policy has been presented and the “single incident” in question involves the concerted action of a large contingent of individual municipal employees, the event itself provides some proof of the existence of the underlying policy or custom.”
871 F.2d 1151, 1156–57 (1st Cir. 1989) (cleaned up) (emphasis added).
As the above makes plain, a single event alone does not a policy make. The First Circuit has recently confirmed this in Velez v. Eutzy, 152 F.4th 292, 306 (1st Cir. 2025). But this language, and the Velez decision, do not mean that a single-event case can never succeed: indeed, as the First Circuit explained just two years after the Bordanaro decision, “[a] claim of inadequate supervision cannot be precluded as a matter of law because only a “single instance” of brutality is alleged[.]” Willhauck v. Halpin, 953 F.2d 689, 714 n. 25 (1st Cir. 1991).
Such a claim can be bolstered by what the Bordanaro court referred to as “post-event evidence,” which can be used by a plaintiff to “shed some light on what policies existed in the [municipality] on the date of an alleged deprivation of constitutional right.” 871 F.2d at 1167. In a recent District of Massachusetts case, that evidence was the unanimity of officer action – or more accurately, inaction – in deciding not to report the drawing of firearms, despite a clear departmental policy requiring such reporting. In that case, “[t]he decision by several individuals in the Stoneham Police Department to disregard reporting policies demonstrates that this was ‘the way things were done and had been done.’” Salem v. Stoneham Police Dep’t, 752 F. Supp. 3d 282, 300 (D. Mass. 2024) (cleaned up).
This of course applies to the case where a group of officers together violate an individual’s rights, and then together conspire to cover up the violation. Bordanaro and Salem together lend significant support to the idea that a plaintiff may be able to show that it was a municipal custom or policy which emboldened or encouraged the officers to act as they did.
