BOSTON — The Department of Justice is suing Boston over its “sanctuary” policies limiting cooperation with federal immigration crackdowns, claiming the city government is shielding “criminal aliens” from deportation.

In a lawsuit filed in U.S. District Court in Boston on Thursday, the DOJ alleges Boston’s sanctuary policies violate federal law and have resulted in the release of “dangerous criminals” from custody who otherwise would be subject to removal, including those convicted of assault, burglary, and drug and human trafficking.

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