For years, decades really, courts and local law enforcement agents across the country have been holding our clients at the request of federal immigration authorities – sometimes for several days or even longer – after they should otherwise have been released. The decision to honor these requests, called immigration detainers, had become commonplace. This formerly commonplace practice of honoring an immigration detainer has undergone increased scrutiny in recent years, as courts have begun to recognize what it truly is: a new arrest, entitled to all the protections of the Fourth Amendment and state constitutional search and seizure provisions. That detainers are issued for civil immigration purposes without a judicial warrant and are executed without any judicial oversight and that they are unaccompanied by any individualized finding of probable cause (instead, there is a boilerplate form) raises serious constitutional concerns.
 
On Monday, however, the Massachusetts Supreme Judicial Court recognized an even more basic flaw in the act of honoring an immigration detainer. State courts and law enforcement officials have engaged in these arrests for immigration enforcement without acknowledging that their authority to arrest is defined and enumerated by State law. In Commonwealth v. Lunn,  http://www.mass.gov/courts/docs/sjc/reporter-of-decisions/new-opinions/12276.pdf the SJC affirmed that Massachusetts does not authorize our courts, jails, or police officers to arrest for civil immigration purposes – even at the request of federal authorities through an immigration detainer. This decision provides important guidance to Massachusetts law enforcement officials at a time when federal immigration authorities have dramatically expanded their enforcement efforts, threatening to interfere with our administration of justice. See Maria Cramer, Courthouse arrests worry attorneys, prosecutors, Boston Globe (Metro June 15, 2017), available at https://www.bostonglobe.com/metro/2017/06/15/ice-arrests-and-around-local-courthouses-worry-lawyers-prosecutors/xxFH5vVJnMeggQa0NMi8gI/story.html
 
But this should also be a message to other states: If your legislature has not authorized your law enforcement officers to arrest based on civil immigration violations, then honoring an immigration detainer is an unauthorized arrest – an unauthorized arrest unaccompanied by any judicial oversight or individualized finding of probable cause.
 
The SJC’s decision in Lunn does not undermine public safety in Massachusetts. Massachusetts law enforcement officers and courts are well-equipped to protect the public, without detaining people for purported civil immigration infractions. A person is only held on an immigration detainer after a Massachusetts court or law enforcement officer has reviewed his case and decided that he should be released – for example, because he’s been found not guilty, or his criminal case has been dismissed, or a judge has determined that he should be released on bail. Moreover, the Court’s decision does nothing to prevent federal immigration officers from arresting people themselves – they simply may not use Massachusetts courts and officers to do their work.
 
Likewise, courts across the United States should not hesitate to find that the act of honoring an immigration detainer is an unauthorized and unconstitutional arrest. Local law enforcement will be able to continue doing what they have always done – protect the public – without being entangled in civil immigration enforcement, where they risk estranging noncitizen witnesses and victims of crimes. I encourage courts to follow the lead of Lunn.