Actually, depending on the situation, you do have that right. Not that I advocate a private citizen using citizen's arrest - unless it is of a person who has broken into their home - but home breakin is NOT the only circumstance where a citizen is privileged to detain a stranger.
Yeah, I thought about that when I was posting, but I didn’t want to imply that into the situation being described, that of a question being asked of another who is not observed committing a criminal act. Great point.