Is it permissible for money obtained through extortion to become lawful after the extorted person forgives the extortionist and the original amount is given as charity?

It is impermissible to take people's money without their consent, for Allah the Almighty says: "O you who have believed, do not consume one another's wealth unjustly but only [in lawful] trade by mutual consent." The money must be returned to its owner. If he forgives you, then you are absolved. As for the profit generated from investing this money, there is a difference of opinion: some say it belongs to the worker, while others say it belongs to the owner of the money. The most equitable view is that the profit should be shared between them because it is the result of both capital and labor combined, and this is the view preferred by Ibn Taymiyyah. Accordingly, half of the profit and the principal capital must be returned to its owner unless he absolves you. Giving charity equivalent to the principal capital does not suffice as a substitute for returning it to its owner, unless he approves your action.