I wonder if there is a word for the situation (or the person involved) when someone is inadvertently helping a criminal without knowing that the person is, in fact, a criminal?
For example, you work as an office-boy in a company, and your boss is asking you to deliver cases to other parties, but you do not know the content of it. In reality, you are delivering suitcases filled with guns or narcotics.
Another example is when you are lodging your cousin who wants to stay with you for a few days but he is a convict, and you are not aware of it yet.
Someone who helps a criminal without knowing it is referred to as an unwitting accomplice (unwitting means not done on purpose and accomplice means a person who helps another person commit a crime):
She was an unwitting accomplice to tax fraud. (She didn’t know that she was helping someone to commit tax fraud)