Often people will pretend that they are totally innocent just to get other people to be claimed as guilty. They will not take accountability for something that occurred or their mistakes. How do you tell if they are this kind of person based off of the way they are talking or using their English?
Second part, What is an idiom that could be used to describe this kind of person? I am writing a story with a character like so in it.
Here's my assumption of what that idiom would be:
He's Just a blind seeker.
I'm not sure if that's accurate or even a real official idiom.