The Maricopa County Sheriff's Office in Arizona, which is run by the controversial Joe Arpaio, is rife with civil rights violations, including the use of excessive force, and systemic problems, the U.S. Justice Department alleges.

An investigation of "America's toughest sheriff," as some call Arpaio, and his deputies found that they have allegedly engaged in a pattern and practice of discrimination against Latinos with misconduct that violates federal laws and  individuals' constitutional rights.

"MCSO engages in a pattern or practice of unconstitutional policing," Thomas Perez, the assistant attorney general for the Civil Rights Division, wrote in a letter to Bill Montgomery, the county attorney for Maricopa County. "Specifically, we find that MCSO, through the actions of its deputies, supervisory staff, and command staff engages in racial profiling of Latinos; unlawfully stops, detains and arrests Latinos; and unlawfully retaliates against individuals who complain about or criticize MCSO's policies."

The Maricopa County Sheriff's Office did not respond to a request for comment or reaction to the Justice Department's action.

The Justice Department's Civil Rights Division has been investigating Arpaio's office since June 2008.  There is also an ongoing criminal investigation into officials at the Sheriff's Office.

Perez noted in the investigative findings letter that there is "reasonable cause to believe that MCSO has committed violations of the First, Fourth and Fourteenth Amendments to the United States Constitution."

The findings note that Latino drivers are four to nine times more likely to be pulled over for a traffic stop than non-Latinos.

The Justice Department found problems with how the Sheriff's office operates the jail by allegedly discriminating against Latino inmates by punishing inmates who do not understand English when officers would give them commands only in English. The report also noted that deputies would allegedly deny Latino inmates critical services and information about obtaining their release and legal information.

"MCSO engages in a pattern or practice of unlawful seizures, including unjustified stops detentions, and arrests of Latinos in violation of the Fourth Amendment to the United States Constitution," Perez alleged in the letter.

During the course of the investigation, the Justice Department has noted, the Maricopa County Sheriff's Office refused to cooperate with the investigation by refusing to turn over documents and making officials available for interviews.  The department reached an agreement with the Sheriff's office to gain access to documents and interviews earlier this year.

"We observed that that MCSO has implemented its immigration enforcement program in a way that has created a 'wall of distrust' between MCSO officers and Maricopa County's Latino residents," the Justice Department noted.

The department's review found some instances of alleged abuse and tactics used by Sheriff deputies, including:

• Deputies allegedly searched a home without a warrant in May 2009 and placed a Latino man and his 12-year-old son in handcuffs, although both were legal U.S. residents.

• A Latino, who was a legal U.S. resident, being arrested after failing to produce a driver's license. The individual provided a valid work visa, Social Security card and Arizona identification card. The individual was jailed for 13 days.

• A Latino U.S. citizen allegedly being driven over by a Sheriff's deputy who failed to pull over his car when the officer flashed his lights but did not use the siren. The individual identified only as D.D. drove to his house for fear of concern about his ethnicity. When D.D. exited the car he was allegedly struck by the deputy's car and pinned under the vehicle. The officer allegedly told other officers to "leave him there" when they arrived.  The man sued the county for $600,000 and the deputy was arrested for aggravated assault.

• Deputies noting poor internal controls and lack of "basic accountability" in the immigration enforcement program.

• The alleged use of false criminal charges against individuals who speak out against the Sheriff's office.

The Justice Department has concerns that the actions of the Sheriff's Office have harmed relations with the Hispanic community, especially because almost one-third of the county's resident's are Latinos. The Justice Department is seeking to implement key reforms in the Sheriff's Office and noted today that it will seek a court order to implement the plan going forward.

"Effective policing and constitutional policing go hand in hand," Perez said in a statement. "Developing and implementing meaningful reforms will assist in reducing crime, ensuring respect for the Constitution, and ensuring that the people of Maricopa County have confidence in MCSO's commitment to fair and effective law enforcement."