PHOENIX (Reuters) - The U.S. Justice Department sued an Arizona sheriff on Thursday for civil rights violations, alleging he and his office intentionally engaged in racial profiling and unlawful arrests of Latinos in violation of their constitutional rights.
The lawsuit cited systemic profiling, sloppy and indifferent police work and a disregard for minority rights by Maricopa County Sheriff Joe Arpaio, a conservative Republican who styles himself as "America's toughest sheriff," and county officials.
"Leadership starts at the top and all of the alleged violations that are outlined in the complaint are the product of a culture of disregard for basic rights... that starts at the top and pervades the organization," Assistant Attorney General for the Civil Rights Division Thomas Perez told reporters.
Perez said the Justice Department sued Maricopa County, the sheriff's office and Arpaio in U.S. District Court in Arizona after trying unsuccessfully for three and a half months to get Arpaio to comply with federal civil rights law.
Arpaio faces re-election in November in the county that includes the Phoenix metropolitan area. He has become the face of hardline local efforts to crack down on illegal immigration, placing him on a collision course with the federal government.
Maricopa County has created inadequately trained special units that are used to target Latinos for unlawful and unjustified arrests; has willfully denied Latino prisoners their civil rights in jail; and under Arpaio's direction has arrested political opponents for no valid reason, the DOJ suit contends.
"At its core, this is an abuse of power case involving Sheriff Arpaio and a sheriff's office that disregarded the Constitution, ignored sound police practices and did not hesitate to retaliate against perceived critics in a variety of unlawful ways," said Perez.
"Constitutional policing and effective policing go hand in hand. The complaint outlines how Sheriff Arpaio's actions were neither constitutional nor effective," he said.
The lawsuit cited the use of a "volunteer posse" or group of untrained civilians that carry out Arpaio's anti-Latino policies in a county of 4 million people that is 30 percent Latino.
Latino drivers in one part of the county are nine times more likely to be stopped than non-Latino drivers engaged in similar conduct, the suit said.
In one case, a sheriff's officer stopped a Latina - a U.S. citizen who was five months pregnant - as she pulled into her driveway and insisted that she sit on the hood of her car.
"When she refused, the officer grabbed her arms, pulled them behind her back, and slammed her, stomach first, into the vehicle three times," the suit said.
Arpaio's combative style and defiance of federal threats have made him a hero to nativists and conservatives who advocate strict border enforcement. Meanwhile he is a pariah to liberals and immigrant rights advocates.
In March, he drew headlines with an assertion that his office had found that President Barack Obama's birth certificate was a forgery. Most Republican critics of Obama have given up pursuing such widely discredited "birther" allegations.
On the eve of the lawsuit alleging racial-profiling, Arpaio released a 17-page document entitled "Integrity, Accountability, Community - The Maricopa County Sheriff's Office 2012," pledging to overhaul his office.
"I do not tolerate racist attitudes or behaviors. We at the Maricopa County Sheriff's Office do not foster a 'culture of cruelty,'" Arpaio said in a statement.
"With that in mind, I required my staff to consider how we can engage in more community outreach, to enhance our law enforcement and detention services and to build public trust. And I asked that this process be undertaken with our critics in mind. Their voices should be heard," he said.
His pledge was too late to avoid a lawsuit, which comes amid a broader battle between the state and the Obama administration over who has the right to implement immigration law.
The U.S. Supreme Court is currently weighing Arizona's defense of its crackdown on illegal immigrants, signed into law by Republican Governor Jan Brewer in 2010.
The law requires police to check the immigration status of people they stop and suspect of being in the country illegally. The measure is among several blocked by a federal judge.
Brewer and backers of the law said it was needed because Washington had failed to secure the porous Mexico border. But Obama and other critics filed suit arguing that it pre-empted federal authority on immigration and made Hispanics the target of racial profiling.
A Supreme Court decision upholding Arizona's law - known as SB 1070 - would be a legal and political setback for Obama as he seeks re-election in November. A ruling striking down the law would be a defeat for Brewer and a setback for Republican White House hopeful Mitt Romney, who supports it.
The case will be closely watched by Alabama, Georgia, Indiana, South Carolina and Utah, which followed Arizona in passing immigration crackdowns. A ruling is not expected until June or July.
Additional reporting by Edith Honan and Daniel Trotta; Editing by Anthony Boadle