If it’s a real crime, they are supposed to refuse absolution until after the penitent turns himself in to the authorities.
I don’t believe that is accurate at all. Absolution is of God and the Church. Turning one’s self in to authorities is relative to many other circumstances. The Penance is but one.
That doesn’t do much for the cause of justice or future crimes commited by that person, does it?
What would happen to a priest that reported a criminal act divulged to him in confession?