Possible BOT/ENGINE user ?

How do you find out if an opponent is maybe using a bot or an engine ?
Is there any way to find this out via analysis of some kind or software ?

Long shot, thought I'd ask, maybe I get lucky.

Yes I'd like to know too..Sometimes with a lower ranked player playing like a grandmaster I wonder.

under site rules in the site map there's a fair play ticket that you can submit cheating accusations.