What is the ruling on supplicating against someone out of a belief that they have committed injustice, only for the accused person's innocence to be later revealed? And will this supplication be answered, knowing that its utterer does not trust others and suffers from a bad presumption?

A supplication that involves aggression or injustice will not be answered, for Allah Almighty says: "Invoke your Lord with humility and in private. Indeed, He does not like aggressors," and for the Prophet's (peace be upon him) saying: "The supplication of anyone of you will be answered as long as he does not pray for a sin or for the severance of kinship ties." It is not permissible to supplicate against someone merely based on the suspicion that they have committed injustice; rather, one must ascertain the truth and have a good opinion of a Muslim. Since remorse is repentance, there is no sin upon you for what you erred in, but you should seek forgiveness for that person and supplicate for their well-being.