The U.S. Supreme Court case with the most bizarre set of facts may well be In Re Neagle (1890). The issue concerned whether U.S. marshal David Neagle was entitled to federal habeas corpus relief after he killed a man who was trying to harm U.S. Supreme Court justice Stephen Field. California prosecutors had charged Neagle with the murder of David Terry, a former chief justice of the California Supreme Court.

The underlying facts begin with an unstable woman named Sarah Hill, who was a mistress to U.S. senator William Sharon of Nevada. Hill claimed that she was married to Sharon and she hired prominent California lawyer David Terry, who had served with Justice Field on the California Supreme Court. Terry sued on her behalf, claiming she was married to Sharon. A trial court denied her claim to marriage. She then appealed to an appeals court. The presiding appeals court judge was Justice Field.

Field denied Hill’s appeal, enraging attorney Terry. When Field ruled against Hill, she went berserk in the courtroom. The marshals attempted to subdue her, but Terry rose to defend Hill, whom he had married while the case was on appeal. Terry punched one marshal and pulled out his Bowie knife to face others. Several marshals, including David Neagle, subdued Terry. Justice Field then sentenced both Terry and Hill to jail time for contempt of court.

In jail, Terry and Hill made threats against Justice Field, causing the U.S. attorney to appoint a marshal to protect Justice Field. The attorney selected Neagle to protect Justice Field. With Neagle at his side, Field then traveled by train to California. Hill and Terry were also on the train. When Hill saw Field, she ran to get her gun and Terry slapped Field twice in the face. Neagle confronted Terry and ordered him to quit assaulting the Supreme Court justice. Neagle shot and killed Terry on the train, as Terry appeared to pull open his jacket to brandish his own weapon.

Hill sought an arrest warrant against Neagle and Field. San Joaquin County sheriff Thomas Cunningham arrested both Neagle and Field, charging them both with murder, even though only Neagle fired the pistol. Neagle was jailed, but Field was released and the charges were dropped against him, presumably because he did not fire the pistol.

Neagle later filed a petition in federal court, seeking his release from the California jail. He prevailed before a lower federal court, prompting Sheriff Cunningham to appeal to the U.S. Supreme Court.