Source: Wall Street Journal

The Obama administration is curbing the powers of an Arizona sheriff who has led one of the most contentious fights against illegal immigrants.

Under an agreement involving local enforcement of federal immigration law, Sheriff Joe Arpaio's deputies will no longer have the authority to arrest suspected illegal immigrants in the streets in the course of their duty.

A senior official with Immigration & Customs Enforcement flew to Phoenix late last month with the revised agreement, which the sheriff signed late last week.

Homeland Security announced in July that all localities participating in the enforcement program -- more than 60 from Alabama to California -- would have to sign revised enforcement deals by Oct. 15. Unlike others participating in the program, Mr. Arpaio will be restricted to determining the immigration status of inmates booked into Maricopa County jails. Vincent Picard, an ICE spokesman in Phoenix, declined to comment. ICE is a unit of the Department of Homeland Security.

Mr. Arpaio was an early participant in a federal immigration program that enlists and trains local police to identify suspected criminal aliens in jails and on the streets. The program, known as 287g, is designed to target drug dealers, gang members and human smugglers.

Since February 2007, Mr. Arpaio has arrested about 30,000 illegal immigrants who were booked into jails in his county. The street-enforcement component, the most contentious portion of the program, resulted in the apprehension of far fewer people suspected of being in the U.S. illegally.

Human-rights activists have said Mr. Arpaio's officers engaged in racial profiling and found pretexts, such as broken tail lights, to arrest undocumented residents of the Phoenix area. The Department of Justice is investigating whether officers used skin color as a pretense to stop Hispanics. Mr. Arpaio has said that his actions were in line with the law.

"They took away my authority on the streets. That doesn't matter because I will still pursue illegals on the streets of Maricopa utilizing the authority I have as the elected official," Mr. Arpaio said Tuesday in an interview.

Homeland Security Secretary Janet Napolitano ordered a comprehensive review of the 287g program shortly after taking office.

A person close to the Obama administration said some DHS officials had been hoping Mr. Arpaio would withdraw from the program altogether when confronted with a watered-down version.

Mr. Arpaio, a headline-grabbing elected official in his fifth term, said: "They thought I wasn't going to sign it. I signed it."

Write to Miriam Jordan at miriam.jordan@wsj.com