The Support Our Law Enforcement and Safe Neighborhoods Act (introduced as Arizona Senate Bill 1070 and commonly referred to as Arizona SB 1070) is a 2010 legislative act in the U.S. state of Arizona that was the broadest and strictest anti-illegal immigration law in the United States when passed. It has received international attention and has spurred considerable controversy.

U.S. federal law requires immigrants older than 18 to possess any certificate of alien registration issued to him or her at all times; violation of this requirement is a federal misdemeanor crime. The Arizona act made it also a state misdemeanor for an immigrant to be in Arizona without carrying the required documents, and required that state law enforcement officers attempt to determine an individual's immigration status during a "lawful stop, detention or arrest" when there is reasonable suspicion that the individual is an illegal immigrant.Police may "transport" said alien to a federal facility "in this state or any other point" where such a facility exists. Arizona HB 2162, §3. The law barred state or local officials or agencies from restricting enforcement of federal immigration laws, and imposed penalties on those sheltering, hiring and transporting unregistered aliens. The paragraph on intent in the legislation says it embodies an "attrition through enforcement" doctrine.Arizona SB 1070, §1.

Critics of the legislation say it encourages racial profiling, while supporters say the law prohibits the use of race as the sole basis for investigating immigration status. The law was amended by Arizona House Bill 2162 within a week of its signing, with the goal of addressing some of these concerns. There have been protests in opposition to the law in over 70 U.S. cities, including boycotts and calls for boycotts of Arizona.

The Act was signed into law by Governor Jan Brewer on April 23, 2010. It was scheduled to go into effect on July 29, 2010, ninety days after the end of the legislative session. Legal challenges over its constitutionality and compliance with civil rights law were filed, including one by the United States Department of Justice, that also asked for an injunction against enforcement of the law. The day before the law was to take effect, federal judge Susan R. Bolton issued a preliminary injunction that blocked the law's most controversial provisions. In June 2012, the U.S. Supreme Court ruled on the case Arizona v. United States, upholding the provision requiring immigration status checks during law enforcement stops but striking down three other provisions as violations of the Supremacy Clause of the United States Constitution.

Provisions U.S. federal law requires immigrants 14 years old or older who are in the country for longer than 30 days to register with the U.S. government and have registration documents in their possession at all times. The Act makes it a state misdemeanor for an illegal immigrant to be in Arizona without carrying the required documentsArizona SB 1070, §3. and obligates police to make an attempt, when practicable during a "lawful stop, detention or arrest", to determine a person's immigration status if there is reasonable suspicion that the person is an illegal alien.Arizona SB 1070, §2. Any person arrested cannot be released without confirmation of the person's legal immigration status by the federal government pursuant to § 1373(c) of Title 8 of the United States Code. A first offense carries a fine of up to $100, plus court costs, and up to 20 days in jail; subsequent offenses can result in up to 30 days in jailArizona HB 2162, §4. (SB 1070 required a minimum fine of $500 for a first violation, and for a second violation a minimum $1,000 fine and a maximum jail sentence of 6 months).Arizona SB 1070, §5. A person is "presumed to not be an immigrant who is unlawfully present in the United States" if he or she presents any of the following four forms of identification: a valid Arizona driver license; a valid Arizona nonoperating identification license; a valid tribal enrollment card or other tribal identification; or any valid federal, state, or local government-issued identification, if the issuer requires proof of legal presence in the United States as a condition of issuance.

The Act prohibits state, county, and local officials from limiting or restricting "the enforcement of federal immigration laws to less than the full extent permitted by federal law" and provides that any legal Arizona resident can sue the agencies or officials in question to compel such full enforcement. If the person who brings suit prevails, that person may be entitled to reimbursement of court costs and reasonable attorney fees.

The Act makes it a crime for anyone, regardless of citizenship or immigration status, to hire or to be hired from a vehicle which "blocks or impedes the normal movement of traffic." Vehicles used in such manner are subject to mandatory immobilization or impoundment. For a person in violation of a criminal law, it is an offense to transport an illegal immigrant "in furtherance" of that person's unauthorized presence in the U.S., to "conceal, harbor or shield" an illegal immigrant, or to encourage or induce an illegal immigrant to immigrate to the state, if the person "knows or recklessly disregards the fact" that the immigrant is in the U.S. without authorization or that immigration would be unlawful. Violation is a class 1 misdemeanor if fewer than ten illegal immigrants are involved, and a class 6 felony if ten or more are involved. The offender is subject to a fine of at least $1,000 for each illegal immigrant involved. The transportation provision includes exceptions for child protective services workers, ambulance attendants, and emergency medical technicians.

Arizona HB 2162 On April 30, 2010, the Arizona legislature passed, and Governor Brewer signed, House Bill 2162, which modified the Act that had been signed a week earlier, adding text stating that "prosecutors would not investigate complaints based on race, color or national origin." The new text also states that police may only investigate immigration status incident to a "lawful stop, detention, or arrest", lowers the original fine from a minimum of $500 to a maximum of $5000, and changes incarceration limits for first-time offenders from 6 months to 20 days.

Background and passage Arizona was the first state to enact such far-reaching legislation. Prior law in Arizona, like most other states, did not require law enforcement personnel to ask the immigration status of people they encountered. Many police departments prohibit such inquiries to avoid deterring immigrants from reporting crimes and cooperating in other investigations.

Arizona had an estimated 460,000 illegal immigrants in April 2010, a fivefold increase since 1990. As the state with the most unlawful crossings of the Mexico–United States border, its remote and dangerous deserts are the unlawful entry point for thousands of immigrants from Mexico and Central American. By the late 1990s, the Tucson Border Patrol Sector had the highest number of arrests by the United States Border Patrol.

Whether illegal immigrants commit a disproportionate number of crimes is uncertain, with different authorities and academics claiming that the rate for this group was the same, greater, or less than that of the overall population. The decreased rate in property crimes was noted in a correction on June 27, 2010. There was also anxiety that the Mexican drug war, which had caused thousands of deaths, would spill over into the U.S. Moreover, by late in the decade 2000, Phoenix had garnered a reputation as America's worst city regarding kidnappings, averaging one kidnapping per day.

Arizona has a history of restricting illegal immigration. In 2007, legislation imposed heavy sanctions on employers hiring undocumented workers. Measures similar to SB 1070 had been passed by the legislature in 2006 and 2008, only to be vetoed by Democratic Governor Janet Napolitano. She was subsequently appointed as Secretary of Homeland Security in the Obama administration and was replaced by Republican Secretary of State of Arizona Jan Brewer. There is a similar history of referendums, such as the Arizona Proposition 200 (2004) that sought to restrict illegal immigrants' use of social services. The 'attrition through enforcement' doctrine had been encouraged by anti-immigration think tanks, such as the conservative Center for Immigration Studies, for several years.

Impetus for SB 1070 was attributed to demographics shifting towards a larger Hispanic population, increased drug trade and human trafficking related violence in Mexico and Arizona, and a struggling state economy and economic anxiety during the late-2000s recession. State residents were frustrated by the lack of federal progress on immigration, which they viewed as even more disappointing given that Napolitano had joined the Obama administration.

The major sponsor and legislative force behind the bill was state senator Russell Pearce, who had long been one of Arizona's most vocal opponents of illegal immigrants and who had successfully pushed several prior pieces of tough legislation against those he termed "invaders on the American sovereignty". Much of the bill was drafted by Kris Kobach, a professor at the University of Missouri–Kansas City School of Law and a figure long associated with the far-right Federation for American Immigration Reform who had drafted immigration bills for many other states. Pearce and Kobach had worked together on prior immigration legislation, and Pearce contacted Kobach when he was ready to pursue stronger state enforcement of federal immigration laws. A December 2009 meeting of the American Legislative Exchange Council (ALEC) in Washington, D.C., produced model legislation that embodied the Pearce initiative.

One explanation for the impetus behind the bill was that ALEC is largely funded by corporate contributions, including some from the private prison industry such as the Corrections Corporation of America, Management and Training Corporation, and GEO Group. These companies would benefit from a large increase in the number of illegal immigrants sent to jail. Pearce later denied that he created the bill for any reason other than to stop illegal immigration. He denied that he submitted the idea to ALEC for any reason other than helping it pass in Arizona and, potentially, in other states.

The bill was introduced in the Arizona legislature in January 2010 and gained 36 cosponsors. The Arizona State Senate approved an early version of the bill in February 2010. Saying, "Enough is enough," Pearce stated figuratively that this new bill would remove handcuffs from law enforcement and place them on violent offenders.

On March 27, 2010, 58-year-old Robert Krentz and his dog were shot and killed while Krentz was doing fence work on his large ranch roughly from the Mexican border. This incident gave a tangible public face to fears about immigration-related crime. Arizona police were unable to name a murder suspect but traced a set of footprints from the crime scene south towards the border. The resulting speculation that the killer was an illegal immigrant increased public support for SB 1070. There was talk of naming the law after Krentz. Some state legislators (both for and against the law) believed, however, that the impact of the Krentz killing has been overstated as a factor in the law's passage.

The bill, with several amendments, passed the Arizona House of Representatives on April 13 by a 35–21 party-line vote. The revised measure then passed the State Senate on April 19 by a 17–11 vote that also closely followed party lines, with all but one Republican voting for the bill, ten Democrats voting against it, and two Democrats abstaining.