In theory, a criminal could try to 'game' the system by doing this - but if he isn't truly repentant, he only cheats himself from a supernatural perspective. And if he manages to get caught (even though the priest can't force him to turn himself in) he certainly doesn't help himself in a civil sense either.
However, if a priest knows that the penitent isn't repentant and has no intention of ceasing the sin that was confessed, then he can withhold absolution (this would be the case in situations such as if the criminal intends to keep committing the crime or even cases such as a divorced person who is 'remarried' and has no intention of giving up the sin of adultery with a new 'spouse'). Such a situation is rare - indeed, few who approach confession come without some resolve to amend their lives with the help of God's Grace - but it does happen.
In the case of the criminals that were moved from church to church committing the same crimes against young boys and girls once it's clear they aren't repentant would the secrecy of the confessional be broken?