The federal trial of Milwaukee County Judge Hannah Dugan began Monday, with prosecutors accusing her of blocking an ICE arrest and defense attorneys arguing confusion over enforcement policy.

Opening remarks by Assistant U.S. Attorney Keith Alexander kicked off an extraordinary trial for a public official. Milwaukee County Circuit Judge Hannah Dugan is charged with obstruction and concealment for her actions this spring during President Donald Trump’s immigration crackdown.

Hannah Dugan faces charges of concealing a person and obstruction after prosecutors allege she interfered when ICE agents attempted to arrest Eduardo Flores Ruiz at the Milwaukee courthouse in April.

Jury selection in the federal trial of Milwaukee County Judge Hannah Dugan begins Thursday. So how does federal court work?