Montana Title 46. Criminal Procedure § 46-6-312. Manner of arrest without warrant

A peace officer making an arrest without a warrant shall inform the person to be arrested of the officer's authority, of the intention to arrest that person, and of the cause of the arrest, except when the person to be arrested is actually engaged in the commission of or in an attempt to commit an offense or is pursued immediately after its commission, after an escape, or when the giving of the information will imperil the arrest.