Trump wants to deport criminals. They're hard to track down.

It can take days or weeks of surveillance and considerable risk to arrest one person with an immigration violation and a criminal record.

The agency has roughly 6,000 deportation agents.

They're staring down a caseload of 7.6 million noncitizens including more than 660,000 with criminal records.

The vast majority aren't in federal custody; Congress pays for 41,500 immigration detention beds nationwide.

The year 2012 , under the Obama administration, saw the highest number of deportations from the interior.

But illegal immigration has fallen dramatically this past year , for various reasons.

The Trump administration stands to inherit a U.S.-Mexico border in which unlawful crossings are at a five-year low.

Congress is poised to massively expand the categories of immigrants ICE must target for deportation.

Bustamante-Cespedez didn't have a final order of removal yet, so he would face an immigration judge.

A judge would determine whether he should be detained or deported or granted a chance to apply to stay in the U.S. The driver who picked him up that morning was also from Bolivia , but he had permission to work in the United States .