A federal judge has ruled that an Arizona sheriff infamous for his tough approach to immigration law enforcement and his office's deputies violated the rights of Latinos by profiling them based on their ethnicity.

Maricopa County Sheriff Joe Arpaio – who styles himself as 'America’s toughest sheriff' and is known for questioning the authenticity of President Barack Obama's birth certificate – was defeated in court on Friday when a federal judge ruled that his crackdown on undocumented immigrants violated the civil rights of Latino residents.

The case against Arpaio was initiated by Manuel de Jesus Ortega Melendres, a Mexican national with a US tourist visa, who claimed he was detained illegally by deputies from Arpaio's office in 2007 after he was stopped in a car near a gathering of Mexican day laborers.

People call for immigration reform outside the U.S. Immigration and Customs Enforcement (ICE), office in Phoenix, Arizona (John Moore / Getty Images / AFP)

Four other plaintiffs – all drivers of Latin origin who believe they were stopped on the basis of their ethnicity and treated worse than other motorists – testified in the case. No monetary retribution was sought in the suit; the plaintiffs called for an end to Arpaio's discriminatory practices.

"The great weight of the evidence is that all types of saturation patrols at issue in this case incorporated race as a consideration into their operations ," Judge G. Murray Snow of the US District Court wrote in his 142-page ruling, Reuters reported.

Judge Murray has prohibited the Sheriff’s Office from racial profiling. Its 800 deputies have been forbidden from stopping a car because Latinos are passengers, and from arresting people without substantial evidence a law has been broken.

Immigration detainees finish lunch at the Immigration and Customs Enforcement (ICE), detention facility in Florence, Arizona (John Moore / Getty Images / AFP)

Human rights activists hailed the ruling: "This is a victory for everyone. Singling people out for traffic stops and detentions because they are Latino is unconstitutional and just plain un-American ,” American Civil Liberties Union (ACLU) director Cecillia Wang said.

Tim Casey, the lawyer for the Maricopa County Sheriff’s Office, vowed to appeal the case and denied that the organization he defended had engaged in racial profiling. He also assured the Sheriff's Office would “comply with the letter and spirit of the court’s decision .”

The ruling against Sheriff Arpaio is seen by many as landmark decision – Arizona, a US state on the border of Mexico, has long been at the forefront for the immigration debate, with local authorities frequently enacting harsh measures to curb illegal immigration.

But federal immigration policy may soon be changing, as a US Senate panel has recently approved a sweeping immigration reform bill, which lays out a 13-year path to citizenship for the country's 11 million illegal immigrants.

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