ICE observers used whistles and Signal chats. Now they face threats of prosecution.

MINNEAPOLIS (FOX 9) - A new docuseries from FOX 9 Documentaries details the Trump Administration's immigration operations in Chicago and Minneapolis that resulted in constitutional challenges, violent tactics and deadly shootings. The three-part series, "Thin I.C.E.", shows how constitutional observers scaled up for the unprecedented immigration operation.

Whistles and Signal

What we know:

One of the enduring sounds from Operation Metro Surge —other than deadly gun shots fired by federal agents —will be the shrieking whistles blown by thousands of constitutional observers.

"Every time that I heard that whistle blow, my stomach would drop," said Zoe Cantu, one of the observers trained to monitor federal immigration agents last winter.

Organizations like Unidos MN started preparing for the Trump Administration's immigration enforcement operations in June 2025.

"We needed to build a rapid response system … it needed to be robust, it needed to go to scale," Jose Avilar, an organizer with Unidos MN, said in an upcoming series by FOX 9 Documentaries.

Thousands of ICE observers

By the numbers:

When Unidos launched its observer training last year, Avilar and other organizers were surprised that nearly a hundred people showed up.

Within weeks, they had to shift to larger venues as the attendance kept doubling.

"[It] went from 200 to 400 to 600," said Luis Argueta. "We got to a point where we had to close registration at 2,000."

Unidos and other organizations eventually trained tens of thousands of observers who monitored neighborhoods, churches and schools.

Local perspective:

They used encrypted Signal chats to recruit, organize and schedule shifts. 

Border Patrol Commander Gregory Bovino acknowledged at the time that federal agents had not anticipated such an organized response in Minnesota.

"What we’ve seen that’s a bit different here is the organization of some of the groups … the groups are a bit better organized," Bovino said at a press conference during the surge. 

"They’ve got some excellent communications," he added.

RICO for whistles

The other side:

Constitutional observers were quickly labeled "agitators’ who were committing crimes by interfering with federal agents.

Rep. Walter Hudson (R-Albertville) argued that blowing a whistle or communicating on Signal should result in a Racketeer Influenced and Corrupt Organizations (RICO) conspiracy — a charge historically used to prosecute Mafia organizations or violent gangs.

"If you were organizing, funding, materially supporting, inciting violations of federal law as an organization, yes, you should be subject to a RICO charge," Hudson said in an interview for the documentary.

U.S. Attorney alleges "Antifa" conspiracy

Why you should care:

Months after Hudson made those comments to FOX 9, U.S. Attorney Daniel Rosen charged 15 people for engaging in an "Antifa" aligned conspiracy to interfere with federal law enforcement during the immigration operation.

ICE protesters recently demonstrated outside the federal courthouse in Minneapolis and called for the charges to be dismissed.

What you can do:

Watch "THIN I.C.E." — a new series by FOX 9 Documentaries. The three-part series includes interviews with numerous constitutional observers and organizers who documented ICE tactics during the surge.

Part one premieres Wednesday, Nov 4, at 10:35 p.m. CT on FOX 9.

ICE assaults rarely charged, regularly dismissed

Dig deeper:

Federal investigations into alleged interference or assaults of agents during immigration operations in Chicago and Minnesota over the past year have rarely led to convictions, according to a FOX 9 Investigators review of court records.

Charges were dismissed against Heather Zemien and Tippy Amundson months after they were surrounded and arrested while observing federal agents in an apartment complex in Brooklyn Park.

"The only thing we did was exercise our right to blow a whistle," said Zemien. 

The majority of cases were never charged or were dismissed and included allegations of insufficient evidence or government misconduct.

Rosen has denied that any cases have failed in any way.

Theresa Kleinhaus, an attorney who sued the Trump Administration over its response to protesters and observers during Operation Midway Blitz, told FOX 32 Chicago that the government’s criminal cases have "utterly fallen apart in very embarrassing ways."

Watch THIN I.C.E. documentary series

What's next:

Thin I.C.E. is a three-part series by FOX 9 Documentaries detailing the Trump Administration's immigration operations in Chicago and Minneapolis that resulted in constitutional challenges, violent tactics and deadly shootings.

Thin I.C.E. Part I: "Worst of the Worst" premieres Wednesday, Nov. 4 at 10:35 p.m. CT on FOX 9, FOX LOCAL and the FOX 9 YouTube channel. 

• Nov. 4 - Thin I.C.E. Part I: "Worst of the Worst"
• Nov. 11 - Thin I.C.E. Part II: "Domestic Terrorists"
• Nov. 18 - Thin I.C.E. Part III: "Chaos"

The Source:  FOX 9 conducted dozens of interviews, analyzed hundreds of court records and reviewed hours of body video footage recorded during immigration operations in Chicago and Minneapolis.