Nov. 2, 2004: Joe Arpaio wins fourth term as Maricopa County sheriff.
Aug. 15, 2005: State’s human smuggling law goes into effect.
March 2, 2006: MCSO deputies make their first arrest under the new law — 52 illegal immigrants packed into two vans on the west edge of the county.
April 2006: Arpaio creates the Human Smuggling Unit, which starts with two deputies. During the next two years, it expands to 18 members.
May 2006: The Human Smuggling Unit stops 14 vehicles loaded with illegal immigrants, the most in any month.
February 2007: U.S. Immigration and Customs Enforcement granted 160 sheriff’s deputies authority to enforce federal immigration law.
April 20, 2007: State awards the sheriff’s office $1.5 million for human smuggling enforcement. Meanwhile, MCSO spends nearly $400,000 on overtime during that pay period, triple its usual two-week extra-hours expense.
Aug. 15, 2007: The Human Smuggling Unit makes its first drop house raid, arresting four people on state smuggling charges.
October 2007: County budget officials notify MCSO that overtime spending has put the agency $1.3 million in the red. Arpaio shutters satellite jails and virtually eliminates overtime.
October 2007 through January 2008: Off-duty deputies start working as security guards at M.D. Pruitt’s Home Furnishings store in Phoenix, where day laborers gather. Advocates on both sides of the immigration issue protest weekly for months.
Jan. 1, 2008: The state employer sanctions law goes into effect. It threatens to revoke business licenses from employers who knowingly hire illegal immigrants.
March 21-22, 2008: MCSO deputies conduct saturation patrols in Phoenix near Pruitt’s. Fifty-six people are arrested, including 39 believed to be illegal immigrants, according to MCSO.
March 27-28, 2008: MCSO conducts sweeps in north Phoenix. Fifty-four are arrested, including 27 people believed to be illegal immigrants.
March 28, 2008: Phoenix Mayor Phil Gordon (pictured) blasts the saturation patrols, escalating public debate over the sweeps.
April 3, 2008: Eight state lawmakers send letter to Arpaio encouraging him to conduct immigration sweeps in the East Valley.
April 3-4, 2008: MCSO conducts saturation patrols in Guadalupe (pictured, right). Forty-five people are arrested, including nine believed to be illegal immigrants. Guadalupe Mayor Rebecca Jimenez publicly accuses MCSO of racial profiling.
April 4, 2008: Gordon sends a letter to U.S. Attorney General Michael Mukasey requesting a federal investigation into whether MCSO is violating civil rights.
April 18, 2008: Arpaio notifies Guadalupe that the sheriff’s office will sever its police services contract with the town in 180 days.
May 6, 2008: Maricopa County Supervisor Mary Rose Wilcox criticizes Arpaio as MCSO begins a two-day saturation patrol in Fountain Hills, Arpaio’s hometown. Twenty people are arrested, including 16 believed to be illegal immigrants.
May 14, 2008: Gov. Janet Napolitano withdraws $600,000 in funding from the sheriff’s office that Arpaio had intended to use for illegal immigration enforcement.
June 10, 2008: Deputies raid two water parks and arrest nine people believed to be illegal immigrants in connection with identity theft and using forged documents to obtain employment.
June 16, 2008: Arpaio announces his 1,000th arrest on state smuggling charges.
June 27-28, 2008: MCSO conducts saturation patrols in Mesa. Mesa police deploy more than 100 officers to keep peace.