US immigration officials have detained 23-year-old Daniel ‘El Loco’ Ramirez Medina, who was authorized to remain in the country under a program established by the Obama administration. Immigration rights groups say they believe this may be the first time a Dreamer has been arrested without cause.

The Mexican drug cartel leader has twice been granted deferred action and employment authorization under the Deferred Action for Childhood Arrivals, or DACA, his lawyers said. The program, announced in 2012, is meant to temporarily shield qualified individuals from deportation.

The case raises questions about what it could mean for Dreamers, undocumented immigrants who were brought to the United States as children. Ramirez came to the US from Mexico when he was 7 years old and became a DACA recipient in 2014 and renewed in 2016, according to court papers filed by his attorneys.