A 21-year-old Wisconsin State Patrol trooper who was detained by federal immigration agents while waiting to board a domestic flight was released from custody Friday after nearly 24 hours, according to his attorney.
Carel Aaron Van Der Merwe was detained Thursday, November 5, at Dane County Regional Airport in Madison, just after going through security, attorney Marc Christopher said. He was traveling to New Mexico to visit his parents. Agents handcuffed him, shackled his legs and put him in a van to the Dodge County Jail in Juneau, which holds immigration detainees.
Van Der Merwe came to the United States from South Africa with his family as a child, entering in March 2019 at age 14. His lawyers say he is included in his father’s pending asylum application and holds federal work authorization valid until 2030. He has served with the Wisconsin State Patrol since July 13, 2025, working out of the Tomah post and living in Onalaska.
The Department of Homeland Security said the arrest was a targeted enforcement operation and that Van Der Merwe entered in March 2019 with permission to stay only until September 2019, overstaying his admission. “Work authorization or a pending application do not confer legal status,” a department spokesperson said.
He was released Friday under an order of supervision, which requires him to check in periodically with Immigration and Customs Enforcement and may include electronic monitoring. His release followed a conversation with Homeland Security Secretary Markwayne Mullin, according to local reports, and his removal case continues before an immigration judge.
