BOSTON — More than 200 immigrants suspected of living in the U.S. illegally were arrested on state and local charges this year but released before federal authorities could take them into custody, according to a new report.

The Center for Immigration Studies, a conservative Washington, D.C think tank, cites data from the Boston offices of U.S. Immigration and Customs Enforcement showing that 495 foreign nationals sought by immigration officials were arrested by local police from March 19 to May 30.

More than half of those suspects were not turned over to federal authorities, the group said, either because local police refused to cooperate with ICE by honoring immigration detainers, or because local agencies released the immigrants before a detainer or warrant was issued.

The suspects were arrested on a variety of crimes ranging from rape, assault and drug trafficking to domestic violence and operating under the influence.

Jessica Vaughn, the group's director of policy, said the data highlights the negative impact of "sanctuary" policies that "shield criminal illegal aliens."

"Such interference with immigration enforcement results in the unnecessary release of criminal aliens who pose a threat to the public, and who should be sent back to their home countries instead of back to our communities," Vaughn said.

Immigrant rights groups blasted the new report as a "false and insulting" attempt to build support for stepped-up immigration enforcement.

"This is a deeply misleading report that uses grandiose rhetoric and cherry-picked examples to depict Massachusetts as a dangerous place where only ICE can protect us," said Marion Davis, spokeswoman for the Massachusetts Immigrant and Refugee Advocacy Coalition.

'Most are misdemeanors'

Davis said most of the immigration violations that result in ICE detainers involve undocumented people charged with misdemeanors, not violent crimes.

"To suggest that we should violate the constitutional rights of hundreds or thousands of people by having police hold them on civil charges, just in case there’s a violent felon in the mix, is absurd," Davis said.

A spokesman for ICE's regional office declined to comment.

The report lists several cases — including a Guatemalan national facing deportation for living in the U.S. illegally who was arrested in Lawrence in February on felony armed robbery charges. The report didn't identify the man but said he was released by Lawrence District Court before ICE agents could serve a detainer.

"Some agencies have adopted additional internal policies that limit or prohibit their cooperation and information-sharing with ICE," the agency wrote in a memo obtained by Vaughn's group. "These policies often result in the release of potentially dangerous criminal aliens back into the community."

Vaughn said ICE data show illegal immigrants who've committed crimes are less likely to show up for court hearings or immigration proceedings.

"There’s no reason for drug traffickers in the country illegally to be walking in and out of jails like it’s a revolving door," she said.

Sanctuary state?

The report comes as state lawmakers are weighing a proposal to declare Massachusetts a "sanctuary state" barring local police from detaining people living in the country illegally. Another proposal, tucked into the Senate version of the budget, would prevent state resources from being used to enforce immigration law and forbid local police from asking about a person's immigration status, among other provisions.

An ICE detainer is issued when an undocumented person has been arrested on criminal charges and federal authorities believe there is probable cause to deport the person. If police comply with the request, ICE takes the suspect into custody.

Several communities, including Lawrence, have passed ordinances restricting cooperation between local police and immigration agents. Salem passed a "Sanctuary for Peace" ordinance, but it does not bar police from cooperating with immigration authorities in criminal cases.

Immigrant rights groups say giving police the authority to cooperate with federal immigration agents makes communities less safe because it dissuades people from reporting crime for fear of deportation.

Opponents of such policies say police should be working with federal authorities to enforce the law, instead of blocking criminals from arrest and deportation.

Republican Gov. Charlie Baker has threatened to veto the so-called "Safe Communities Act,” declaring Massachusetts a sanctuary state, if it reaches his desk. But he has said he doesn’t oppose cities and towns that declare themselves sanctuaries.

Last year the Supreme Judicial Court ruled local police don't have the power to detain people on immigration charges unless they face criminal charges. The court also ruled police cannot cooperate if ICE asks for someone to be held until they can arrive, but said the Legislature has the power to require that.

In response to the court's ruling, Baker filed legislation that seeks to authorize, but not require, state and local law enforcement to honor specific ICE detainers for "aliens who pose a threat to public safety."

Meanwhile, Republican lawmakers, including Rep. Jim Lyons, R-Andover, filed a bill giving state and local police the authority to enforce federal immigration law by detaining, with or without a warrant, those suspected of being in the U.S. illegally.

President Donald Trump, a Republican, has vowed to crack down on "sanctuary" communities if they refuse to cooperate with immigration officials, but recent federal court rulings have largely blunted the impact of those policies.

Last week, Attorney General Jeff Sessions singled out Lawrence during a speech in Concord, New Hampshire in which he connected illegal immigration, sanctuary policies and the rise of drug gangs. He cited the recent federal prosecutions of an opioid ring based in the city, which included several illegal immigrants.

His words drew a sharp rebuke from Lawrence Mayor Dan Rivera, who accused the nation's top law enforcement official of making "libelous" statements.

Christian M. Wade covers the Massachusetts Statehouse for The Salem News and its sister newspapers and websites. Email him at