What is the ruling on selling to one who is known to have acquired their money through deceptive and unlawful means?

This person's wealth is either lawful or unlawful. If it is lawful, then it is permissible to deal with him in all permissible matters. If it is unlawful, then dealing with him requires elaboration. The issue of stratagems and unofficial methods needs clear clarification to determine whether the wealth acquired through them is lawful or unlawful, as a person may acquire through stratagem what is rightfully his, or what is not rightfully his.