ICE reveals legal theory behind warrantless immigration arrests

When ICE agents make civil immigration arrests, they are required to obtain an administrative warrant, which supervisors within ICE sign off on to confirm that probable cause exists to make the arrest.

But the law has a carve-out that allows ICE agents to make an arrest without a warrant if they believe the person is "likely to escape" before a warrant is obtained.

Lyons wrote in the memo that an "alien is 'likely to escape' if an immigration officer determines he or she is unlikely to be located at the scene of the encounter or another clearly identifiable location once an administrative warrant is obtained."

ICE previously interpreted "likely to escape" to mean "flight risk," which Lyons said was an improper view of the law. A flight risk describes someone who might not show up to a future hearing, but Lyons said ICE agents making "on-the-spot determinations" in the field do not necessarily have enough information to know if someone is a flight risk prior to arresting them.

The memo noted that agents should document in a government form, as soon as possible after the arrest, what factors they considered when apprehending someone without a warrant.

DHS Assistant Secretary Tricia McLaughlin said in a statement to Fox News Digital the memo was "nothing new."

"This is just a reminder to officers to be [keeping] detailed records on their arrests," she said, adding that "authorities under USC 1357 and, of course, reasonable suspicion are protected by the U.S. Constitution."

"It would cover essentially anyone they want to arrest without a warrant, making the general premise of ever getting a warrant pointless," she said.

"Defendants have adopted a policy of making arrests using a deficient standard under both the [Immigration and Nationality Act] and well-settled constitutional principles," Howell wrote.