Anyone can get a background report on anyone. Arrest & conviction information is PUBLIC infirmation unless it was something that happened as a child & a petition was made to the court to have those records sealed.....not the case in this situation.
Very similar to the was my almost x -H is.....if he says something is, he believes it & tries to get everyone else to believe him also....ALL the lies he has convinced himself of.
Don't even bother with people like that. Chances of change even when continually confronted about their lies just doesn't happen.....& it gets worse the more you know them....at least in my case.