Cardinal Law, formerly of Boston, who was at the center of the sex abuse by priests scandal ignored protests from victims and celebrated mass for Pope John Paul II in St Peter’s Basilica.
I have to say, whether a murderer or a child molester, the place for sinners to be is before the Lord. I'm no Catholic, and I certainly do not agree with their theology of the Eucharist, but if I understand anything at all about their faith-practice the mass is where Catholic sinners need to be.
That said, an unrepentant sinner, stiff-neck and all, can go before the Lord until his face turns blue but God will say what David said to himself in Psalm 51, "Sacrifice, O LORD, You don't want or I would give it. You, O God, desire a broken heart, a humble and contrite spirit." [my paraphrase]
Those who call themselves by the name of God, Jews and Christians, take the name of the Lord in vain when they go before the throne of Grace and Mercy IN their sins ... unconfessed and unrepentant.
We would all do well, when trying to get a wrong righted, to remember that God said, "Vengeance is Mine, I will repay!" He did not say, "I might repay!" or "I can repay!" but that He "will repay"!