In tests that companies give to determine honesty, there are a number of signals that a person is suspicious ....
Yes, I think that you can have a gut instinct, backed up by checks.
I used to work in a place, where I was one of a team granting large loans. I followed the usual checks, each time, and then, if all was well, I signed the application.
Twice I refused to sign. The bosses were not happy. I said that, if they wanted the loans to go through, then they would have to sign the applications themselves, because they just did not feel right to me. They did, the loans went through ~ and neither of those two men ever paid back a single penny.
I would phone them up and hear them saying that they were out ~ or just laughing at us.
I am so glad that it wasn't me who signed ~ I would probably have been sacked