Is it permissible to spend stolen money, taken from a non-Muslim, which cannot be returned to its owner, by giving it as charity to the poor and needy, while seeking forgiveness from Allah?

There is no disagreement among scholars regarding the prohibition of stealing the wealth of Muslims and non-Muslims alike. Upon repentance, it is obligatory to return the stolen property to its owner. If it is impossible to reach the owner or their heirs, then it should be given as charity for good causes or to the poor. This act of disposal is done with the intention of purification (from the illicit gain), and the thief remains at liberty to either confirm the charity or pay the owner their right if they appear. In this latter case, the reward goes to the owner.