Supporters say the percentage of immigrants who can’t afford a lawyer for their cases is an affront to due process rights.
Detainees may arrive in Aurora from the U.S.-Mexico border or New York City, far away from family and a known place.
He was ordered released after the federal government lost its immigration board appeal.
Removals have more than doubled in a year in Colorado and Wyoming, from 1,033 to 2,535 through September of last fiscal year. Arrests are up too, though not by as much.
Nationwide, ICE says it arrested 40 percent more people under the Trump administration than in the prior year under President Obama.
An immigration judge ordered Lima-Marin's release on Oct. 5 but gave federal authorities 30 days to appeal.
Immigration and Customs Enforcement officials have 30 days to appeal, and an ICE official told The Denver Post the agency was working on a response.
“This has never been more important than now,” Hancock said in announcing the agreement. To the undocumented people living in the city, he said, “We've got your back.”
"We must encourage these 'sanctuary' jurisdictions to change their policies," Attorney General Jeff Sessions said in announcing the move.
Denver council members want to formalize and in some cases, expand policies that limit cooperation with federal immigration officials.