> (4) A person (other than a federal law enforcement officer) who is assisting a federal law enforcement officer acting in the course of his or her duties may, without warrant, use a surveillance device for any purpose:
(a) that involves listening to, or recording, words spoken by a person; and
(b) that is referred to in subsection (1);
if the first‑mentioned person is the speaker of the words or is a person, or is included in a class or group of persons, by whom the speaker of the words intends, or should reasonably expect, the words to be heard.