Ramsey County officials said they are investigating the Jan. 18 arrest of a Hmong American man by federal immigration officers, with county leaders citing video evidence and seeking federal records they say they need to determine whether state or federal crimes were committed.

At a news conference Monday, Ramsey County Attorney John Choi and Sheriff Bob Fletcher said they are pursuing information from the Department of Homeland Security for their investigation into the arrest of ChongLy “Scott” Thao, 56, which occurred in St. Paul. They said Ramsey County includes Minnesota’s state capital, and that the arrest was captured on video in a way that raised questions among neighbors.

Fletcher said there are “many facts we don’t know yet,” but said one point was not in dispute: that Thao “is and has been an American citizen,” and that county officials believe there was no warrant as far as they have been able to determine. Fletcher also said officers took Thao from his home “forcibly” and drove him “around” in freezing conditions while he was only wearing underwear and a blanket.

Choi said the county is trying to determine whether any crimes were committed that it could prosecute under state or federal law. He also said St. Paul police were investigating another case related to the immigration crackdown for potential violations, but he declined to provide details about that separate investigation.

Thao declined to comment on the county’s Monday announcement. In a January interview with The Associated Press, Thao said agents who arrested him eventually realized he was a longtime U.S. citizen with no criminal record and returned him to his home after a couple of hours.

The county leaders said DHS, which oversees ICE, has refused so far to cooperate with Ramsey County, or with other state and local investigations into shootings by federal officers of two U.S. citizens in Minneapolis during the Trump administration’s immigration crackdown. They said the state and Hennepin County—covering Minneapolis—sued the Trump administration last month to gain access to evidence they say they need to independently investigate three shootings by federal officers, including the killings of Renee Good and Alex Pretti. As covered in related reporting, the dispute is part of an effort by Minnesota officials to obtain records they say are necessary to investigate federal actions.

Fletcher said the county believes it has jurisdiction to investigate. “There is no such thing as absolute immunity for federal agents,” he said. He added that there is “qualified immunity” for law enforcement in different capacities, but he argued that seizing a person from his home while the person is an American citizen is not protected in the same way.

ICE said it disagreed with the county’s characterization. In a statement, the agency said ICE does not “kidnap” people and called Ramsey County’s announcement “nothing but a political stunt to demonize ICE law enforcement.” The ICE statement did not address the county’s request for evidence, but it asserted that investigators “concluded sexual predator targets had ties to the property,” a point Thao and his family denied.

County officials said they sent their requests for evidence in writing. They said the director of the trial division in the county attorney’s office, Hao Nguyen, said the office wrote to DHS, ICE and local federal prosecutors on March 20 outlining the evidence they are seeking, and Nguyen said they want to identify who worked that day and where the agents reported. Nguyen said the request also seeks information on recordings and witness interviews, including “digital recordings, witness interviews, video recordings.”

Choi said the county set a deadline of April 30. After that date, officials said they could sue or convene a grand jury. The sheriff urged people with evidence to come forward.

ICE later said it was seeking two convicted sex offenders, but Thao told the AP in January that he had never seen the two men before and that they did not live with him. The Minnesota Department of Corrections later said one of the two wanted men was still in prison.

Videos captured the arrest scene, according to county officials, including people blowing whistles and horns and neighbors shouting at more than a dozen gun-toting agents to leave Thao’s family alone.