Local Law Enforcement may cooperate with Immigration Enforcement

A review of applicable rulings shows that local law enforcement may cooperate with ICE (immigration enforcement)

In a March 22, 2005 ruling, in Muehler v Mena, in unanimous decision from a Court known for its 5-4 splits, the United States Supreme Court essentially said that asking about immigration status during a lawful police contact (or, by implication, any lawful contact) was as fundamental a question as asking for name, address and date of birth. Indeed, the Court made clear that no predicate "independent reasonable cause' need exist to inquire into immigration status. It is the Law of the Land.
Calling a decision by the 9th Circuit Court of Appeals “faulty,” the Supreme Court held that “mere police questioning [regarding one’s immigration status] does not constitute a seizure.” The Court continued its landmark ruling on this issue by stating that “the officers did not need reasonable suspicion to ask Mena for her name, date of birth, or immigration status.”...
If there were even a hint that merely asking about immigration status is discriminatory (as claimed by proponents of the proposed Ordinance), then you might expect to have had at least one dissenter in that decision: Justice Ruth Bader Ginsberg. Justice Ginsberg was general counsel of the ACLU from 1973 to 1980 and sat on its National Board of Directors from 1974 to 1980. Justice Ginsberg's joining the entire court in this decision speaks volumes about its judicial wisdom and legal common sense.
Congress expressly intended for local law enforcement to act in cases in which officers have reason to believe that an individual is in the country illegally, even though immigration law enforcement is not their primary responsibility. In 1996, Congress passed and President Clinton signed legislation that protects individual officers who act to enforce federal immigration laws, even if their departments have non-cooperation policies.

The September 8, 2005 article Local police can enforce laws on immigration, states:

...A recently unearthed U.S. Justice Department memo says state and local cops can make arrests after traffic stops if they find civil immigration violations, such as someone overstaying a visa.
No specific federal authority is needed for local officers to make such arrests, according to the 2002 memo, which came to light in a recent court case....
The Associated Press reported Thursday the 2002 memo was issued by then-Attorney Gen. John Ashcroft and his staff. It overturned a 1996 letter from Justice Department lawyers that said state and local police could enforce only criminal immigration violations, such as sneaking across a border....

Excerpts from Testimony of James Jay Carafano, Ph.D. Before the House Select Committee on Homeland Security:

The DHS and the states should pursue, and Congress should support, the use of Section 287 of the Immigration and Naturalization Act (INA) as a mechanism for state and local law enforcement to enforce the immigration aspect of border security. Section 287 (g) of the INA provides authority for state and local enforcement to investigate, detain, and arrest aliens on civil and criminal grounds. Officers governed by a §287 (g) agreement must receive adequate training and operate under the direction of federal authorities. In addition, in a civil lawsuit, the state law enforcement officers would be considered to have been acting under federal authority, thereby shifting liability to the federal government and providing additional immunity for the state law enforcement officers enforcing federal laws.

Excerpts from Testimony on The 287(g) Program: Ensuring the Integrity of America’s Border Security System through Federal-State Partnerships, Kris W. Kobach, Professor of Law, University of Missouri (Kansas City) School of Law, July 27, 2005

The inherent authority of local police to make immigration arrests was recognized by the Justice Department’s Office of Legal Counsel (OLC) and was announced by Attorney General Ashcroft on June 6, 2002. OLC’s unequivocal conclusion was that arresting aliens who have violated either criminal provisions of the Immigration and Nationality Act (INA) or civil provisions of the INA that render an alien deportable “is within the inherent authority of the states.”1 Such inherent arrest authority has never been preempted by Congress. This inherent authority is simply the power to arrest an illegal alien who is removable, detain the alien temporarily, and then transfer the alien to the custody of the Bureau of Immigration and Customs Enforcement (ICE).
In contrast, Section 287(g) delegates authority that is considerably broader than the power to merely arrest an alien and transfer him to ICE custody. Section 287(g) encompasses the spectrum of basic enforcement powers. Such 287(g) authority includes not only the power to arrest and transfer, but also the power to investigate immigration violations, the power to collect evidence and assemble an immigration case for prosecution or removal, the power to take custody of aliens on behalf of the federal government, and other general powers involved the routine enforcement of immigration laws. This broader enforcement authority can only be delegated to state and local law enforcement agencies through a formal Memorandum of Understanding (MOU), which effectively deputizes members of state or local law enforcement agencies to perform the “function[s] of an immigration officer.” 8 U.S.C. § 1357(g).
It has become a cliché since 9/11 to say that enhanced state-federal cooperation is essential if we are to improve our homeland security. All too often those words are devoid of real meaning. However, Section 287(g) is a program that facilitates systematic, structured cooperation with proven results. I wholeheartedly urge this Committee to support its expansion.

Excerpts from Testimony on Immigration and the Alien Gang Epidemic: Problems and Solutions, by Heather Mac Donald, Senior Fellow, Manhattan Institute for Policy Research, before the House Judiciary Subcommittee on Immigration, Border Security, and Claims, April 13, 2005:

...Sanctuary laws are a serious impediment to stemming gang violence and other crime. Moreover, they are a perfect symbol of this country’s topsy-turvy stance towards illegal immigration.
Sanctuary laws, present in such cities as Los Angeles, New York, Chicago, Austin, Houston, and San Francisco, generally forbid local police officers from inquiring into a suspect’s immigration status or reporting it to federal authorities. Such laws place a higher priority on protecting illegal aliens from deportation than on protecting legal immigrants and citizens from assault, rape, arson, and other crimes....
Sanctuary laws violate everything we have learned about policing in the 1990s. Police departments across the country discovered that utilizing every law enforcement tool in their tool chest against criminals yielded enormous gains....

The report, State and Local Authority to Enforce Immigration Law - A Unified Approach for Stopping Terrorists, by Mr. Kris W. Kobach, Center for Immigration Studies, June, 2004, states:

This Backgrounder briefly summarizes the legal authority upon which state and local police may act in rendering such assistance and describes the scenarios in which this assistance is most crucial. It does not cover the provisions of Section 287(g) of the Immigration and Nationality Act (INA) (that is, Section 133 of the Illegal Immigration Reform and Immigrant Responsibility Act (IIRAIRA) of 1996 titled "Acceptance of State Services to Carry Out Immigration Enforcement"), since the scope of such delegated authority is evident on the face of the Act. Rather, this Backgrounder describes the inherent arrest authority that has been possessed and exercised by state and local police since the earliest days of federal immigration law.

Open borders and sanctuary city proponents claim illegal aliens have not violated criminal law, only civil law, and thus that this distinction makes illegal entry into the U.S. a less serious matter. The Attorney General of New York clearly points out that this is incorrect. Below is part of his letter to a New York attorney:

You have asked whether New York law enforcement officials are authorized to make warrantless arrests for violations of the federal Immigration and Nationality Act ("INA" or "Act"). 8U.S.C. ch. 12. There is no definitive authority in the New York state courts holding that state and local police officers may make warrantless arrests for federal crimes. However, it appears likely that if the question were to be presented directly, the state courts would so hold.
If state and local officers do have such authority under state law, the INA permits them to arrest an individual without a warrant where the arresting officer has probable cause to believe that the individual has committed a criminal violation of the Act. Importantly, reasonable belief that a person has committed a civil violation of the Act does not provide a valid basis for an arrest. Therefore, a person’s status as illegally present in the country, which is a civil violation of the INA, without evidence that the person illegally entered the United States (a violation of the criminal provisions of the Act), does not, perforce, provide probable cause that the person is subject to arrest for violation of any criminal provision."
"Under the Act, "illegal alien" may mean an alien who has illegally entered the country, which is a criminal offense under § 1325, or an alien who legally entered but is illegally present in the United States, which may be only a civil violation."

Thus, a definite legal distinction exists between a) evidence that a person is in the U.S. illegally, which may not have been caused by illegal entry - which is a civil violation, 2) evidence that the person has entered the U.S. illegally, which is a criminal violation.
Note that the Attorney General is stating that state and local authorities do have the authority "to make warrantless arrests for federal crimes," meaning that they can arrest people for criminal (but not civil) violations of immigration law even if no warrant has been issued.
See the relevant portion of the INA, which refers to Title 18 of the United States Code, which is titled "Crimes and Criminal Procedures".