There is a person in my current daily life who never admits his wrongs. He is always quick to blame others first and always believes that he is not wrong. Even when he is proven wrong, he still believes he shouldn't be sorry and isn't wrong.

Is there a single-word adjective to describe this behavior? If not, a better way to describe this person would also make do.

While stubborn and irresponsible fit, I feel like they don't tell the whole story. By this, I mean if I were to say to others that he is very stubborn and irresponsible, it is not implicitly implied that he blames others and never acknowledges his own fault.

Edit: I believe my question is different because the person will also never acknowledge their wrongdoing. On top of blaming others, even after it has been proven to be their fault, they will not admit wrong doing. So aside from blaming others, they refuse to acknowledge the possibility that they have committed a mistake.