Yes, Macbeth killed Banqo and Duncan. Neither man did anything to him, and by all accounts they were both his friends. Yet he did not hesitate to take them out of the picture to get what he wanted, when he thought they stood in his way.
Macbeth's brutal slaying of his enemy Macdonwald in Act I points to his wrath. He is spiteful as he acts in contempt of the predictions of the witches who predict that he will be overcome by he "who is not born of woman" by having all in the path of his "vaulting ambition" murdered.