F.B.I. agents arrested a Milwaukee county judge today on charges of obstructing immigration agents. They accused the judge, Hannah Dugan, of guiding an undocumented immigrant through a side door in her courtroom while the agents waited to arrest him in a public hallway.

The arrest was a major escalation in the Trump administration’s battle with local authorities over deportations. President Trump and his top advisers have repeatedly assailed “local judges” and vowed to prosecute local officials who do not assist federal immigration enforcement efforts.

The F.B.I. detailed the accusations against Dugan in a court document, which you can read here. Federal agents said she was “visibly upset and had a confrontational, angry demeanor” when the authorities came to arrest Eduardo Flores-Ruiz, a citizen of Mexico who was in her courtroom to face domestic violence charges.

Dugan, according to the F.B.I., “escorted Flores-Ruiz and his counsel out of the courtroom through the ‘jury door,’ which leads to a nonpublic area of the courthouse.” When agents spotted Flores-Ruiz leaving, they chased after him and arrested him. Kash Patel, the bureau’s director, wrote on social media that Dugan “intentionally misdirected federal agents.”

Dugan, who is widely known in Wisconsin’s progressive circles for working on behalf of low-income people, was released today after a brief appearance as a defendant in federal court in Milwaukee.

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