An interesting issue is whether a state may prosecute a federal official for a
breach of state criminal law while acting within the scope of federal duties. The
answer is no, because the federal official has immunity from the state criminal
law, derived from carrying out federal law or duties and thus protected by the
Supremacy Clause- the supremacy of federal law over state law. The threshold
issue is that the federal official must have been working in the scope of his
duties at the time. This issue was first faced by the Supreme Court in
Neagle, 135 U.S. 1 (1890). In this unique case, a federal marshal killed a
California man in defense of Justice Field, who was a member of the U.S.
Supreme Court. The man had previously made violent threats against Justice
Field, and Neagle was assigned to protecting him. In a belligerent encounter,
the man slapped Justice Field to provoke a fight, and allegedly reached into his
breast pocket. Neagle, fearful the man was going to pull out a weapon, fatally
shot him. The man turned out to be unarmed, and a California sheriff arrested
Neagle on murder charges.
On writ of habeas corpus, the U.S. Supreme Court released Neagle and made
clear that state law is displaced if it imposes burdens on a federal officer's
attempts to protect federal interests or execute federal law, even if no federal
statute specifically authorizes the federal official's conduct, as was the case
here. Neagle established a two-prong test for this type of immunity from state
criminal law: (1) Was the officer performing an act that federal law authorized
him to perform? (2) Were his actions necessary and proper to fulfilling his
federal duties? If the federal officer satisfies this test, he or she is immune
from prosecution for violation of state law.
A similar issue was brought forth more recently in the Ruby Ridge case, Idaho
v. Horiuchi, 215 F.3d 986 (9th Cir. 2000). Horiuchi was an FBI officer who
fatally shot an unarmed woman during an FBI raid on a ranch in Idaho. He had
intended to shoot the armed man near to her. The state of Idaho subsequently
brought criminal charges against the federal officer for involuntary
manslaughter of the woman. The court, relying on
Neagle, dismissed the
charges. The officer was immune from the state charges through the
Supremacy Clause because he satisfied the two prong test. Horiuchi was acting
within the scope of his duties at the time, and he "reasonably thought" his
actions were necessary and proper.
If the officer fails this test, he is subject to the state criminal prosecution. In
either case, a Bivens civil action may be brought by the individual against the
federal officer for the alleged misbehavior. Also, the U.S. Department of Justice
could choose to prosecute the federal officer, even where the state can not.