WASHINGTON — The Supreme Court on Thursday made it harder to strip citizenship from naturalized Americans. It also refused to grant new trials to defendants in a notorious 1984 Washington murder case and to a Massachusetts man whose lawyer failed to object to closing the courtroom for part of his trial.

Stripping Citizenship

The justices unanimously rejected the government’s position that it could revoke the citizenship of Americans who made even trivial misstatements in their naturalization proceedings.

During arguments in April, several justices seemed indignant and incredulous at the government’s hard-line approach in the case, Maslenjak v. United States, No. 16-309.

They asked about a form that people seeking American citizenship must complete. It requires applicants to say, for instance, whether they had ever committed a criminal offense, however minor, even if there was no arrest. A government lawyer, in response to questioning, said that failing to disclose a speeding violation could be enough to revoke citizenship even years later.