To protect the perps? If a perp confess to a priest in the hope of absolution the priest will tell him he must take the proper legal steps to gain absolution i.e. confess also to the police. With this law in force the perps will not go to the priest in the first place and will not hear that requirement to pay temporarily for the sin. Perhaps there are not many who worry enough about the future of their souls enough to go to the police at the priest’s bidding but there are surely more than will without the priest laying out for them the consequences for their immortal soullls.
Whatever.
The state needs to stay out of the confessional and the Church.