“They have no legal basis for why they detained her or why they’re holding her or why they’re trying to deport her,” said her spouse, Desiree Miller. And immigration officials have yet to provide her or her family any clear answers, she added.

Since her arrest on 3 August, Santiago’s case has alarmed immigration advocates across the US, as it illustrates the increasing vulnerability of hundreds of thousands of young people who arrived in the US as children and were granted temporary protections from deportation through the Obama-era Daca program.

Although there have been no regulatory changes to the program, the administration has tried to strip 525,000 Daca recipients, also known as Dreamers, of benefits. In July, Tricia McLaughlin, a Department of Homeland Security (DHS) assistant press secretary, claimed, falsely, that “Daca does not confer any form of legal status in this country” and urged recipients to self-deport.