More: The allegations go beyond a single confrontation between a protester and a federal agent. They highlight a growing conflict over how far the federal government can go in enforcing immigration and security operations inside U.S. cities"and how firmly courts can enforce limits on that power.

With a judge's restraining order already in place, claims that agents ignored it touch on core questions of accountability, the rule of law, and the balance between executive authority and civil liberties on American streets.

The document, filed on behalf of journalism organization the Chicago Headline Club and other plaintiffs, claims that agents from DHS violated a temporary restraining order (TRO) limiting their use of force during protests.

The filing identifies the agent as part of a federal team led by Bovino, the head of the U.S. Border Patrol's Chicago operations.

According to the plaintiffs, a federal officer "pointed a pepper ball gun and then a real gun at declarant Chris Gentry, a combat veteran who was lawfully standing on the side of the road voicing his opposition as agents were driving by in their vehicles."

The filing states that the officer "said bang, bang,' and you're dead liberal.'"

The incident reportedly took place on October 23, during demonstrations in Little Village following federal operations earlier in the week.

Gentry was described as unarmed and not engaged in any unlawful activity.

The same filing also alleges multiple uses of tear gas and pepper munitions by federal agents in violation of Judge Sara L. Ellis's TRO, which restricted the use of crowd-control devices unless there was "an immediate and serious threat of physical harm."

The plaintiffs say the conduct documented on video shows "extreme violence against peaceful and innocent American civilians."