[JURIST] A judge for the US District Court for the District of Arizona [official website] ruled [opinion, PDF] Friday that Maricopa County Sheriff Joe Arpaio [official website] and his department engaged in unconstitutional racial profiling during the execution of immigration patrols. The Department of Homeland Security (DHS) [official website] originally gave the Maricopa County Sheriff’s Office (MCSO) authority to enforce federal immigration law under the Immigration and Nationality Act (INA) [8 U.S.C. Sec. 357(g), text] with up to 160 officers. The MCSO then issued procedures under DHS guidance instructing officers to “consider race or ‘Mexican ancestry’ as one factor among others'” in executing “immigration enforcement operations” pursuant to federal law. The DHS later revoked the MCSO’s authority under the INA, but, according to the court, Sheriff Arpaio and his deputies continued to “operate under the erroneous assumption” that they had authority to enforce alleged violations of federal immigration law. Sheriff Arpaio and the MCSO subsequently implemented a policy in which race constituted grounds for probable cause for the purposes of searching homes and vehicles during traffic stops. The court held:

…[T]he MCSO has no authority to detain people based only on reasonable suspicion, or probable cause, without more, that such persons are in this country without authorization… [I]n the absence of additional facts that would provide reasonable suspicion that a person committed a federal criminal offense either in entering or staying in this country, it is not a violation of federal criminal law to be in this country without authorization in and of itself. Thus, the MCSO’s…policy that requires a deputy…to detain persons she or he believes only to be in the country without authorization…[constitutes an] unreasonable seizure under the Fourth Amendment to the Constitution.

Defense counsel for Sheriff Arpaio and the MCSO have announced plans to appeal [NYT report] the decision in the coming days.

In May 2012 the US Department of Justice (DOJ) filed suit [JURIST report] against Maricopa County, Arizona, the MCSO,\ and Sheriff Arpaio alleging that Arpaio and his department engaged in a pattern or practice of discriminatory and unlawful law enforcement actions against Latinos. In June lawyers for Sheriff Arpaio asked the US District Court for the District of Arizona in a motion to dismiss the lawsuit [JURIST report] pending against him that claims his office discriminated against Latinos and disregarded their constitutional rights. Also in June Maricopa County asked the judge to dismiss the county [JURIST report] from the DOJ’s lawsuit against Sheriff Arpaio.