Yes, we all are murderers. But this murderer is a converted murderer. Through the ages the church has given him a beautiful name, he is called the penitent. That he is penitent is evident. The whole world knows that.
Penitence begins by admitting our sin.
And he has done that in the preceding verse. We indeed justly. And that surely implies that he feared God even though the other did not. The fear of God was implanted in his heart. And he showed it.