MADISON, Wis. — A Wisconsin State Patrol trooper detained by federal immigration agents as he tried to board a flight to visit his family was released from custody a day later under an order of supervision, while his attorney and the Department of Homeland Security dispute whether a man the government authorized to work — and a state authorized to pin a badge on — is in the country lawfully at all.
U.S. Immigration and Customs Enforcement agents arrested Carel Aaron Van Der Merwe, 21, on Nov. 5 at Dane County Regional Airport, just after he passed through security for a flight to New Mexico to visit his parents, according to his attorney, Marc Christopher. The Department of Homeland Security said the arrest was a targeted enforcement operation. Christopher said agents handcuffed Van Der Merwe, shackled his legs and drove him to the Dodge County Detention Facility in Juneau, which holds ICE detainees.
Van Der Merwe was released Nov. 6 under an order of supervision, Christopher said. The order requires him to check in with ICE periodically, and he will likely be monitored electronically, possibly through an application on his cellphone rather than an ankle bracelet. Federal detainee records show him out of custody. His immigration case continues, and he will have to defend it before an immigration judge.
The Department of Homeland Security said Van Der Merwe entered the United States in March 2019 with permission to remain until September 2019.
“He entered the country in March 2019 with legal permission to stay until September 2019. In defiance of our nation’s laws, he overstayed his admission,” a department spokesperson said in a statement. “Work authorization or a pending application do not confer legal status in the U.S.”
The department’s earlier statement said Van Der Merwe would remain in ICE custody pending removal proceedings. It did not explain his release a day later.
“DHS reversed the horrendous Biden-era policy that allowed aliens in our country illegally to jet around our country. Under President Trump, DHS will no longer tolerate this,” the spokesperson said. “This administration is working diligently to ensure that aliens in our country illegally can no longer fly unless it is out of our country to self-deport.”
Christopher said Van Der Merwe came to the United States from South Africa with his family on visas at age 14 and is included on his father’s pending asylum application. The family applied for asylum on the grounds they were persecuted — a family member had been attacked, Christopher said — and has waited seven years for the case to be heard. Van Der Merwe holds federal work authorization valid until 2030.
“That is just absurd and ridiculous,” Christopher said of the government’s position. “They’ve been here lawfully. They have been waiting for their application to be adjudicated and to be decided by immigration.”
His law firm said in a written statement: “ICE says it is going after people who break the law. Here, it has detained someone whose job is to uphold it.” The firm added: “His release does not erase what he and his family have been through. There is still no explanation why DHS detained him or why exactly he is now being released.”
Van Der Merwe wanted to serve in the U.S. military but could not because he is not a permanent resident, Christopher said. He earned a criminal justice degree at New Mexico Military Institute, researched which states would let him do similar work with his status, and chose Wisconsin, whose State Patrol allows noncitizens with valid work authorization to serve. The Wisconsin Department of Transportation said he has been employed by the State Patrol since July 13, 2025. He graduated from the State Patrol Academy on Nov. 21, 2025, as part of the 71st Recruit Class, and was assigned to Monroe County, according to the department. He lives in Onalaska and works out of the Tomah post. He has no criminal record.
The State Patrol said it is aware of the situation and confirmed his employment. It has not said whether his duty status has changed.
U.S. Rep. Derrick Van Orden of Wisconsin said he contacted the secretary of homeland security about the case.
Christopher said he believes the Transportation Security Administration tipped off ICE when Van Der Merwe bought his ticket, and that agents were waiting for him at the airport. That account has not been confirmed by either agency.
“I just told him I wanted him to get back, get reacclimated, just get settled, because I know he’s gone through a very dramatic experience,” Christopher said of his client. “You’re going to use your resources to go after this guy? You’re going to use our tax dollars to detain this guy? It doesn’t make any sense.”
