Is it permissible to remind people of the corruption of one who has died?

If there is a deceased person who was greatly corrupt, and we warn his companions who remain, saying, for example, "Beware of the actions of so-and-so"?
If the corruption is apparent and the sins are manifest, there is nothing wrong with it. When the Prophet (peace and blessings be upon him) passed by a funeral and they spoke ill of the deceased, he said: . He did not rebuke them, and this is understood to be on the condition that his sins were manifest. Therefore, one whose sins are manifest has no backbiting; there is no backbiting regarding him.