PHOENIX (AP) - Federal authorities plan to announce their findings Thursday in a civil rights investigation of an Arizona sheriff's office accused of using discriminatory tactics in its signature immigration patrols.
KJZZ 91.5 FM will broadcast the planned press conference live at 10 a.m. Thursday with the help of KTVK-3TV.
   The U.S. Justice Department has been investigating Maricopa County Sheriff Joe Arpaio's office since June 2008 for alleged discrimination, unconstitutional searches and seizures, and for having an English-only policy in his jails that discriminates against people with limited English skills.
   The self-proclaimed toughest sheriff in America has been a national political fixture who has built his reputation on jailing inmates in tents and dressing them in pink underwear, selling himself to voters as unceasingly tough on crime and pushing the bounds of how far local police can go to confront illegal immigration.
   The federal agency had previously provided little details of its probe, but Arpaio believed the inquiry was focused on the 20 immigration patrols known as ``sweeps'' that his office has conducted since January 2008.
   During the patrols, deputies flood an area of a city - in some cases, heavily Latino areas - over several days to seek out traffic violators and arrest other offenders. Illegal immigrants accounted for 57 percent of the 1,500 people arrested in the sweeps, according to figures provided by Arpaio's office.
   Critics said Arpaio's deputies target people during the patrols for minor traffic infractions based on their skin color so they can ask for proof of citizenship. Arpaio denied the allegation, saying people are stopped if deputies have probable cause to believe they have committed crimes and that deputies later find many of them are illegal immigrants.
   Apart from the civil rights probe, a federal grand jury also has been investigating Arpaio's office on criminal abuse-of-power allegations since at least December 2009 and is specifically examining the investigative work of the sheriff's anti-public corruption squad.
   The squad's cases against two county officials and a judge collapsed in court before going to trial and have been criticized by politicians at odds with the sheriff as trumped up. Arpaio has defended the investigations as a valid attempt at rooting out corruption in county government.
   More than any other local police boss in the nation, Arpaio has pushed the bounds of what local officers can do to crack down on illegal immigration.
   He began doing immigration enforcement in 2005 after the Legislature passed a ban on immigrant smuggling and voters became frustrated over the problems from the state's porous border. He set up a hotline to report immigration violations.
   Over nearly the last three years, he has raided 56 businesses suspected of breaking a state law by knowingly hiring illegal immigrants. The raids led to more than 370 criminal arrests of illegal immigrants accused of using fake documents to get jobs and in two civil cases against employers for illegal hiring.
   Arpaio had 100 deputies specially trained so they could make federal immigration arrests, but U.S. Immigration and Customs Enforcement in October 2009 stripped them of that power. A defiant Arpaio continued his immigration efforts by using state laws.
   Critics have said Arpaio has demonized illegal immigrants in a bid to win support from voters. His supporters said the sheriff is the only local police boss who has really done anything about illegal immigration.
   The sheriff has complained that the civil rights investigation is politically motivated, singling out Phoenix Mayor Phil Gordon, who in the spring of 2008 had asked the Justice Department to investigate Arpaio's immigration efforts.
   During its investigation, the Justice Department filed a lawsuit alleging that Arpaio's office wouldn't hand over records and wouldn't give access to jails, employees and inmates. The lawsuit was settled this summer after getting cooperation from the sheriff's office.
   A separate lawsuit in which a handful of Hispanics alleged racial profiling in Arpaio's sweeps remains alive in federal court.
   The judge in that case found grounds to sanction the sheriff's office for having thrown away and shredded officers' records of traffic stops made during the sweeps, but hasn't yet imposed a penalty.
   The sheriff's office said the destruction of records was an honest error that sprung from a top official not telling others in his office to preserve the documents.
   Later, some sweeps-related emails that were thought to have been deleted by the sheriff's office turned out to have been saved by the county as part of an unrelated lawsuit.
   Among the huge volume of saved emails were some that showed some deputies circulated offensive jokes about Mexicans.