A Washington state mother and her 6-year-old son have been released after spending more than three weeks in US immigration detention due to a brief trip to Canada and a small paperwork mistake, her attorney told CNN on Saturday.

The city's policies "thwart federal immigration enforcement to the detriment of the interests of the United States," U.S. Attorney General Pam Bondi said.

A nonprofit immigration support group is suing Homeland Security over the release of records related to traffic stops.

The district will distribute family preparedness packets that include know-your-rights information, emergency contact updates, and tips on designating a backup caregiver in case a parent is detained.

Gov. Ron DeSantis has said the location in the rugged and remote Everglades was meant as a deterrent against escape, much like the island prison in California that Republicans named it after. The detention center has an estimated annual cost of $450 million, according to a public database.