The Department of Homeland Security said it was revising a program that authorized local police to enforce federal immigration law — a controversial aspect of U.S. border policy.

Opponents said the program, known as 287g, was intended to identify criminal aliens but instead has led to racial profiling; it allowed local police to identify and arrest illegal immigrants for such minor infractions as a broken tail light. Program supporters said it has been an effective tool for combating illegal immigration.

The new guidelines sharply reduce the ability of local law enforcement to arrest and screen suspected illegal immigrants. They are intended to prevent sheriff and police departments from arresting people "for minor offenses as a guise to initiate removal proceedings," according to Homeland Security. The program will instead focus on more serious criminals.

"In a world of limited resources, our view is that we need to focus first and foremost on people committing crimes in our community who should not be here," said John Morton, Assistant Secretary of U.S. Immigration and Customs Enforcement. Morton said his agency would sign new contracts with local law enforcement that would bolster federal oversight.

In the past two years, more than 120,000 suspected illegal immigrants were identified through the program, and most ended up in deportation proceedings. By comparison, ICE removed 356,739 illegal immigrants from the U.S. during the fiscal year ended Sept. 30, 2008 — a 23.5% increase over the 2007 total.

The most active local enforcer has been Joe Arpaio, the sheriff of Arizona's Maricopa County. He said Friday he would continue pursuing illegal immigrants, arguing that state laws allow neighborhood crime sweeps and worksite raids.

"If I'm told not to enforce immigration law except if the alien is a violent criminal, my answer to that is we are still going to do the same thing, 287g or not," said Arpaio. His deputies have identified in jail or picked up on the streets more than 30,000 illegal immigrants in the Phoenix area. "We have been very successful," said the five-term sheriff.

The Department of Justice is investigating whether Arpaio's deputies have used skin color as a pretense to stop Latinos suspected of being illegal immigrants.

Obama's policy change is expected to bolster his standing with Latinos and some Democratic legislators. The administration is seeking to set the stage for a sweeping overhaul of immigration legislation that could put millions of illegal workers on the path to U.S. citizenship.

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