I happen to be a pretty good lie detector. Recently, I avoided a scam on eBay where some guy tried to buy over $400 of stuff from me, and his paypal account didn't seem right, so I investigated and found it was a high school boy from England using hacked paypal accounts to buy computer related toys on line. How? There was an obvious discrepancy in his emails and a pattern of speech that sounded evasive and dishonest to me.
When the liar is in front of you, you need to look for micro-expressions that come when a person is uncomfortable in speaking something that they do not agree with and do not like being forced to say. They can be anything from facial tics to stutters at the critical word to awkward stumbling pauses at the moment of untruth. See if you can spot any apparent microexpressions in this discussion between John Walsh and ex-Congressman Foley.
Then guess which member of that conversation is Maf54 in this inappropriate email exchange.