It is true that some of the world’s most horrible people have never been criminally convicted or jailed. Just look at the headlines
But a simple review of home country arrest and conviction records could weed out the vast majority those already guilty of violence, social offenses, trafficking and frauds. Those are the most likely to reoffend once let into the Kingdom.
I don’t think one person comes from China or anywhere else then SUDDENLY becomes a major money launderer, drug dealer, or fraudster.