Hundreds of Venezuelan and Salvadoran nationals were sent from the United States to the notorious maximum security CECOT facility in El Salvador.
A federal judge, in a setback for the Trump administration, has said she plans to order the release of a wrongly deported Salvadoran migrant while he awaits trial on human smuggling charges.
Kilmar Armando Abrego Garcia, 29, was summarily deported to a maximum security prison in El Salvador in March and brought back to the United States this month.
His case has become a key test of President Donald Trump's hardline deportation policies.
Abrego Garcia was immediately arrested on his return and charged in Nashville, Tennessee, with smuggling undocumented migrants around the United States between 2016 and 2025.
Abrego Garcia has pleaded not guilty to the charges and a federal magistrate judge said in a ruling on Sunday that prosecutors had not made a convincing argument that he should be detained pending trial.
"The government alleges that Abrego is a long-time, well-known member of MS-13," the notorious Salvadoran gang, Judge Barbara Holmes said in her 51-page ruling.
"But Abrego has no reported criminal history of any kind... and his reputed gang membership is contradicted by the government's own evidence."
"Overall," the judge said, "the strength of the factors weighing in favor of release outweighs all other factors in favor of detention."
Holmes acknowledged, however, that even if she orders Abrego Garcia's release at a hearing on Wednesday he would likely be immediately taken into custody by federal immigration agents to face potential removal proceedings.
"That suggests the Court's determination of the detention issues is little more than an academic exercise," she said. "That suggestion is understandable. But the foundation of the administration of our criminal law depends on the bedrock of due process."
Abrego Garcia was living in the eastern state of Maryland until he became one of more than 200 people sent to the CECOT prison in El Salvador as part of Trump's crackdown on undocumented migrants.
Most of the migrants who were summarily deported were alleged members of the Venezuelan gang Tren de Aragua, which the Trump administration has declared a foreign terrorist organization.
Justice Department lawyers later admitted that Abrego Garcia -- who is married to a US citizen -- was wrongly deported due to an "administrative error."
Abrego Garcia had been living in the United States under protected legal status since 2019, when a judge ruled he should not be deported because he could be harmed in his home country.