Colorado Attorney General Phil Weiser filed a civil lawsuit against a Mesa County Sheriff’s Office deputy who tipped ICE off to a college student who has overstayed her visa. 

Weiser said in a news release Tuesday announcing the lawsuit aims to require the deputy “follow state laws that bar state agency and local government employees from cooperating with federal officials on immigration civil enforcement actions.”

On June 5, a University of Utah student was pulled over by Mesa County sheriff’s Deputy Alexander Zwinck for following a semitrailer too closely.

Caroline Dias Goncalves was asked where she was born and was released with a warning.

But after exiting Interstate 70 at Loma, Immigration and Customs Enforcement agents stopped, arrested and took her to a detention center in Aurora.

Dias Goncalves, who was born in Brazil and came to the U.S. under a tourist visa when she was 7, has been living in Utah for 12 years. She overstayed her visa about a decade ago and has a pending asylum case.

During the 20-minute traffic stop, Zwinck, a K9 officer assigned to the Sheriff’s Office drug interdiction team, shared Dias Goncalves’ information with a Signal drug interdiction communication group. This communication group included a number of local, state and federal law enforcement agencies that focus on the highways of western Colorado.

Dias Goncalves’ lawyer now claims that the sharing of information was improper in a case that puts yet another spotlight on Colorado’s policy, which bars local law enforcement from cooperating with federal agents on immigration enforcement. This year, Colorado legislators expanded the law’s prohibition on information sharing to all political subdivisions of the state.

Weiser agreed. 

“Deputy Alexander Zwinck violated Colorado law by working with federal immigration officials to detain a 19-year-old Utah woman after a routine traffic stop last month, according to the lawsuit filed today in Mesa County District Court,” according to the press release. “The lawsuit asserts that Deputy Zwinck had no right to share, or inquire into, the driver’s personal identifying information for the purpose of assisting with federal civil immigration enforcement and asks the court for an order enjoining the deputy from engaging in similar unlawful conduct in the future.”

“State law specifies that Colorado law enforcement officers are dedicated to enforcing Colorado law and do not do the work of the federal government to enforce immigration law,” said Weiser in the release. “In this case, the driver was detained by immigration authorities because of actions by Colorado law enforcement despite the absence of any criminal activity on her part.”

Weiser said during a press conference Tuesday the lawsuit is against Zwinck in his personal capacity, but it doesn’t seek fines — but that would be allowed under the law.

Investigators are also looking at if any other laws were violated that the AG has the authority to enforce. 

On June 19, the sheriff’s office announced that Zwinck had been placed on administrative leave pending the outcome of an internal administrative investigation into whether or not Dias Goncalves’ information was shared improperly.

This investigation, according to MCSO, would also seek to understand “if and when MSCO’s employees were made aware that the information shared for drug interdiction efforts was being utilized for immigration enforcement.”

On Tuesday, a MCSO spokesperson provided this update: “The Mesa County Sheriff’s Office is within one week of completing the administrative investigation into the June 5, 2025, incident involving Ms. Diaz Goncalves. We are committed to transparency in this process and, as such, once the administrative investigation is complete we will provide a formal statement.”

Dias Goncalves, a recipient of the TheDream.US national scholarship, which helps students unlawfully staying in the U.S. go to college, spent 15 days in the ICE detention center, which she described as “the hardest days of my life.” She was released on bond and has returned to her family.

This story is developing and will be updated.

Colorado Politics reporter Marissa Ventrelli and Denver Gazette freelance writer Rachael Wright contributed to this story.