Montes had been brought to the United States when he was 9 years old, and he had been protected from deportation from President Barack Obama's Deferred Action for Childhood Arrivals (DACA).
Montes had left his wallet in a friend's auto, so he couldn't produce his ID or proof of his DACA status and was told by agents he couldn't retrieve them.
Juan Manuel Montes, 23, was deported in February, but his fate came to light after his lawsuit was announced by his legal team.
Montes told USA Today he grabbed a bite and was waiting for a ride in Calexico, Calif., when approached by a U.S. Customs and Border Protection officer. Montes was not carrying his ID, which would have proved his DACA status, and agents refused to let Montes retrieve it, according to the report.
A #DACA recipient was deported in the middle of the night without access to a lawyer.
"Juan Manuel was funneled across the border without so much as a piece of paper to explain why or how", Nora Preciado, a staff attorney at the National Immigration Law Center, said in a statement.
A statement from U.S. Customs and Border Protection says that Montes was arrested for "illegally entering the U.S.by climbing over the fence in downtown Calexico". "No one should have to file a lawsuit to find out what happened to them".More news: Britain's prime minister to seek early election on June 8
King posted a photo of a beer on Twitter, saying "Border patrol, this one's for you". DHS claims that Montes' DACA status expired in 2015 and that their records do not show that he was issued a renewal.
This makes Montes the first undocumented immigrant protected under DACA to be deported during the Trump administration.
Since taking office, Trump has followed through on his campaign pledge to crack down on illegal immigration by signing executive orders to step up enforcement against the estimated 11 million undocumented immigrants living in the U.S. The new policy calls for expanding the criteria for detaining and deporting undocumented immigrants and hiring thousands of new agents.
His attorneys asked CBP and Border Patrol for documents relating to his detention and removal and were told to file a Freedom of Information Act request.
At least 10 Dreamers are in federal custody, according to United We Dream, an advocacy organization made up of DACA enrollees and other young immigrants, USA Today reported. Just last month Secretary Kelly promised me that no one with DACA would lose this protection unless they violated the terms of DACA.
"We look forward to presenting our case to the court, because our client has the right to know why and how he was physically removed from the United States when he had permission to live and work here", Mónica Ramírez Almadani, an attorney with Covington & Burling LLP in Los Angeles, said in a statement.
Montes has a record: three traffic violations and a shoplifting charge. On Tuesday, Iowa Rep. Steve King, a Republican who constitutes the white nationalist portion of the Trump base, had this to say about the news of a young man being split from his family.