25 CFR § 11.301
Arrests
February 24, 2021
(a) Arrest is the taking of a person into police custody in order that he or she may be held to answer for a criminal offense.
(b) No law enforcement officer shall arrest any person for a criminal offense except when:
(1) The officer shall have a warrant signed by a magistrate commanding the arrest of such person, or the officer knows for a certainty that such a warrant has been issued; or
(2) The offense shall occur in the presence of the arresting officer; or
(3) The officer shall have probable cause to believe that the person arrested has committed an offense.