Under a pilot program begun by the Trump Administration in 2017, more than 1,000 children were separated from their parents and held in US custody while their parents were deported.

Now, more than two years after that pilot program ended, NBC News reports that 545 of the children remain in federal custody because their parents cannot be located by the federal government or independent agencies working on the children’s behalf.

This pilot program was the prelude to the court-overturned child separation police implemented in 2018.  Under the 2018 policy, parents and children were separated, but they all remained in US custody.  During the pilot program, the adults were returned to their native country, while the children remained in the US.

“It is critical to find out as much as possible about who was responsible for this horrific practice while not losing sight of the fact that hundreds of families have still not been found and remain separated,” said Lee Gelernt, deputy director of the ACLU Immigrants’ Rights Project. “There is so much more work to be done to find these families.”

Courts put together an independent task force to try to locate and identify the parents of the children.  Many opted to have the custody of the children turned over to relatives in the United States, some afraid or unable to return to the US.  Twenty-five families are attempting to make the trek back to the US for potential reunification.

Hundreds of parents, however, remain unaccounted for or could not be found.