Mich. Comp. Laws § 764.18: Arrest; under warrant; duty of officer.

Sec. 18.

Where an arrest is made under a warrant, it shall not be necessary for the arresting officer personally to have the warrant in his possession but such officer must, if possible, inform the person arrested that there is a warrant for his arrest and, after the arrest is made, shall show such person said warrant if required, as soon as practicable.