## Facts

- Justice Stephen J. Field, assigned to ride circuit in California, faced threats from David S. Terry, a former state judge with a history of hostility toward Field arising from prior litigation and contempt proceedings.
- The Attorney General directed the U.S. Marshal in California to assign Deputy U.S. Marshal David Neagle to protect Justice Field during travel connected to Field’s judicial duties.
- At a train-station dining room in Lathrop, California, Terry approached Field from behind and struck him; Terry was reputed to be violent and to carry a large knife.
- As Terry appeared poised to strike again, Neagle shot and killed Terry, asserting the shooting was necessary to protect Justice Field from a lethal assault.
- California authorities arrested Neagle for murder and held him in the San Joaquin County jail under Sheriff Thomas Cunningham; Field was released, but Neagle remained detained.
- The United States sought a writ of habeas corpus in federal court under Revised Statutes § 753, contending Neagle was detained for an act done in pursuance of federal law and duty.

## Issues

1. Whether a federal court may grant habeas relief to release a federal officer held by a state for homicide when the officer acted in pursuance of federal law within the meaning of Revised Statutes § 753.
2. Whether the Executive Branch had authority, absent an express statute providing judicial bodyguards, to assign a deputy marshal to protect a Supreme Court Justice traveling for official duties.
3. Whether actions taken by a federal officer within the scope of such federal authority preclude state criminal prosecution.

## Decision

- The Supreme Court affirmed the federal circuit court’s order discharging Neagle from state custody.
- The Court held that § 753 authorizes federal habeas relief when a person is held by a state for an act done in pursuance of federal law, and the reviewing court may determine both law and facts necessary to decide whether the detention is lawful.
- The Court concluded that protecting a Justice traveling to perform judicial duties is a federal function and that a Justice is in the discharge of duty while traveling as well as while sitting in court.
- The Court held that the President’s duty to ensure faithful execution of the laws, together with statutes defining marshal powers, supported the assignment of Neagle to protect Justice Field.
- On the facts found by the circuit court, Neagle acted within his federal duty and reasonably used lethal force to prevent a perceived imminent deadly attack; therefore, California could not detain him for murder.

## Legal Principles

- Federal habeas relief is available to release a person held by state authority for acts performed in pursuance of federal law, including actions taken by federal officers in executing federal duties.
- Under the Supremacy Clause, a state may not enforce its criminal process against a federal officer for conduct authorized by federal law and necessary and proper to performing federal functions.
- The Executive Branch may take measures not expressly specified by statute when reasonably necessary to protect the operation of federal law, including protecting federal judges when credible threats arise.
- A Supreme Court Justice traveling as required for official judicial assignments is engaged in official duty and is entitled to federal protection during such travel.
- Statutes granting U.S. marshals powers comparable to state sheriffs in executing law support reasonable use of force, including lethal force when necessary, in the performance of federally assigned protective duties.

## Conclusion

The Court held that a deputy U.S. marshal assigned to protect a Supreme Court Justice could not be held by a state on murder charges for using lethal force in the course of that federally authorized protective duty, and federal habeas corpus was properly used to discharge the officer from state custody.


In re Neagle, 135 U.S. 1 (1890)