You won’t notice any difference in arrest procedure in Baltimore City. That is, unless you’re an illegal immigrant, and even then only after the fact. A federal program to check the fingerprints of arrestees against immigration records, which has been phasing in across the country since 2008, has finally and abruptly come to Baltimore. Mayor Stephanie Rawlings-Blake (who wants more, not fewer, people living in the city) and immigrant advocates have voiced their concerns with the program — and its sudden implementation — but it barely requires the cooperation of the city or the Baltimore Police Department.

That’s because the program, called Secure Communities, is really a collaboration between two federal organizations. Baltimore already sends fingerprints of people who have been arrested to the FBI. Secure Communities only requires that the FBI pass those fingerprints on to Homeland Security.

Secure Communities already has 162,940 deportations to its credit nationwide, 670 from Maryland. Critics fear the program’s deportations could gut immigrant communities, lead to less police cooperation among immigrants, and leave many children in the United States — who may be legal citizens — without parents. Maybe they could rename it Millions of Children Left Behind.