Civil trial begins for Arizona's Sheriff Joe Arpaio High noon is approaching for Maricopa County Sheriff Joe Arpaio. A civil trial against the Arizona law enforcement official -- known for his tough stance on illegal immigration -- begins in Phoenix today, with foes accusing him of racial profiling and of illegally discriminating against Latinos. Groups led by the American Civil Liberties Union are suing Arpaio and the state's most populous county, charging that they targeted Latinos as part of the sheriff's get-tough policy on illegal immigration. Arpaio, who used frequent television appearances to build a reputation as a tough-talking lawman hard on criminals, is expected to take the stand at some point during the several weeks of the civil trial in federal court. The suit is important in helping define the policies of the local sheriff's office, but it's just one legal skirmish that Arpaio is facing. The U.S. Department of Justice is also suing the sheriff, his office and Maricopa County, charging civil-rights violations. In addition, a federal grand jury has been investigating Arpaio's office for allegedly abusing its law enforcement powers and for other possible instances of public corruption. The heart of the current case, known as Melendres vs. Arpaio, is the charge that Arpaio's office regularly stops people who look Latino to check their immigration status. The officials are also accused of stopping Latinos more frequently and for longer periods of time than non-Latinos. There is no penalty at stake in the proceedings, but the ACLU is seeking to have the sheriff's office change its policies. Arpaio and the Maricopa County Sheriff's Office "have unlawfully instituted a pattern and practice of targeting Latino drivers and passengers in Maricopa County during traffic stops," the ACLU says on its website. MCSO's practices discriminate on the basis of race, in violation of the Equal Protection Clause of the Fourteenth Amendment, and have resulted in prolonged traffic stops and baseless extended detentions, in violation of the Fourth Amendment. In its zeal to rid the community of persons that it believes are undocumented immigrants, MCSO has violated the civil rights of countless U.S. citizens and lawful immigrants. The complaint outlines the specifics of the case: Manuel de Jesús Ortega Melendres, one of those suing, said he was stopped by police while riding in a car driven by a non-Hispanic white man whom officers thought was speeding. At the stop, deputies asked to see Ortega Melendres" identification. He says he handed over his U.S. visa, Mexican voter registration card and a copy of his permit from the Department of Homeland Security. Nevertheless, the police asked him to leave the car, patted him down, handcuffed him and detained him for hours. "Because of Mr. Ortega's experience with the Maricopa County sheriff's officers, he is now afraid," the complaint says. Mr. Ortega is afraid that he will be thrown in jail without any explanation, without any rights, and without any opportunity to get help even though the federal government of the United States has issued a visa to him that gives him permission to be here. Arpaio, who is up for reelection in November, is not commenting but denies his office discriminates against Latinos. "This office aggressively enforces all local, state and federal laws in order to combat the growing illegal immigration epidemic in Maricopa County," according to a statement on the sheriff's website. Deputy sheriffs are specifically trained to identify indicators that a person or persons might be in this country illegally without violating their constitutional rights. In many ways, the case is a precursor to the federal civil-rights lawsuit filed against Arpaio in May. That case goes further, however, arguing that Arpaio's office retaliated against its critics, punished Latino jail inmates for speaking Spanish and failed to adequately investigate sex-crimes cases. No trial date in that case has been set. Arpaio has argued that the federal lawsuit is a politically motivated attack by the Obama administration, with which the sheriff has sparred on a variety of issues. Just this week, Arpaio released the results of his group's investigation about Obama's birthplace, again questioning the president's legitimacy. The issue resurfaces periodically despite Hawaiian officials' repeated explanations that the president was born in their state. Justice Department officials say the Arpaio inquiry began during the previous Bush administration. Food's sticker shock: A look at drought and crop damage Chick-fil-A's anti-gay-marriage stance triggers online uproar Lawn chair pilots: Balloons kept taking us up -- and into storm