I'm going to revisit this topic this week in light of the Australian government's recent announcement that a royal commission (a major government public inquiry into an issue in Commonwealth Realms) will be conducted to investigate sex abuse claims in institutions across Australia including the Catholic Church. Before I go on, allow me to make this one thing very, very clear:
I do not condone crimes that are sexual in nature (or any crime for that matter) no matter whom has committed them and from what institution they were affiliated with at the time. As a Catholic I am deeply ashamed and embarrassed by clergy and religious that have committed such crimes against the young and or vulnerable. These are despicable and reprehensible acts. I am in no way defending these clergy or religious. One instance of abuse or crime committed by a priest or church worker is one too many and I applaud the Australian Catholic Bishop's Conference's (and archdioceses around the country) cooperation and compliance with the government in bringing justice to those whom are guilty and closure to those that have been hurt by these vile acts.
Back to Confession, and this is what outlined in the Church's Code of Canon Law about the seal (canons 983 and 984):
Can. 983 §1 The sacramental seal is inviolable. Accordingly, it is absolutely wrong for a *confessor in any way to betray the **penitent, for any reason whatsoever, whether by word or in any other fashion.
§2 An interpreter, if there is one, is also obliged to observe this secret, as are all others who in any way whatever have come to a knowledge of sins from a confession.
Can. 984 §1 The confessor is wholly forbidden to use knowledge acquired in confession to the detriment of the penitent, even when all danger of disclosure is excluded.
§2 A person who is in authority may not in any way, for the purpose of external governance, use knowledge about sins which has at any time come to him from the hearing of confession.*the priest
The seal is inviolable, but sadly there are some who hold position in public office that would like to see that changed especially where confessing to participation in crime(s) is concerned. Rescinding the seal would obviously change the nature of the Sacrament of Reconciliation irrevocably, and dare I say make the penitent think twice about approaching a priest for confession to confess any sin(s). But making comment about the future of this sacrament is for another time; I only desire to emphasise how Confession should work especially in the case of the penitent confessing to a crime.
A person whom approaches the Sacrament of Reconciliation is assumed to be truly sorry for the sins they have committed, otherwise why would they seek reparation in the first place? Before absolution is given, the penitent is asked to say the Act of Contrition prayer, and this is a prayer - as the title suggests - which demonstrates that the penitent is truly sorry for what they have done and genuinely desires to seek forgiveness. The Act of Contrition I was taught as a youngster and I recite to this day goes like this (other versions can be found here):
Oh my God,
I am very sorry that I have sinned against you.
Because you are so good, and with your help,
I will try hard not to sin again.
Before this step, however, the priest will offer us counsel and gives us penance to perform. In short, penance is an act of prayer or an act that will help make reparation for the harm we have done. The penance assigned by the priest is described this way (bolded for emphasis):
The penance the confessor imposes must take into account the penitent's personal situation and must seek his spiritual good. It must correspond as far as possible with the gravity and nature of the sins committed. It can consist of prayer, an offering, works of mercy, service of neighbour, voluntary self-denial, sacrifices, and above all the patient acceptance of the cross we must bear. Such penances help configure us to Christ, who alone expiated our sins once for all. They allow us to become co-heirs with the risen Christ, 'provided we suffer with him.'" - CCC, par. 1460
If, for example, I have confessed to giving in to my anger and said something hurtful to someone as a result of that, the priest might encourage me - as part of my penance - to approach that person and apologise for what I said/did. Otherwise the priest might instruct me to recite a prayer to allow me to reflect the peace we find in God in order to channel my emotions more appropriately.
Suppose a penitent (be they a lay person, clergy, or religious) during Confession confesses to committing a crime (and let's assume it's a serious crime, i.e. something a bit more serious than speeding or parking illegally... not that I condone such things!). By attending Confession it is assumed that the penitent is contrite and truly sorry for the sin(s) they have committed and by being contrite they express a willingness to make reparation for what they have done. It as this point during Confession that the priest assigns penance, and one would assume that based on what we read in the Catechism (see above) that a penance fitting for the penitent would be to turn themselves in to the authorities, right? As a matter of fact, a priest cannot actually assign such a penance. Such a penance would forcibly incriminate the penitent and indirectly violate the Seal of Confession. Under the confessor's counsel the penitent would be encouraged to turn themselves into the authorities so that the course of justice may be undertaken (this is separate to penance).
Once the Act of Contrition is made an absolution is given, the penitent, no matter what sin or crime they've committed, is forgiven and they have repaired their relationship with God and the Church; this is the effect of the Sacrament of Reconciliation. What happens from there on in, if a crime has been committed, rests in the recesses of the penitent's conscience. If they have committed a crime heinous in nature and harmed any number of persons then one would hope that the penitent would do the right thing and submit to the authorities.
The key thing to understand about the Seal of Confession is this: the only person in the confessional that is bound by the seal is the confessor (the priest). The sins confessed are the penitent's; they may at their own liberty divulge the sins they have confessed to and may tell anyone they please (including the authorities). As people of conscience and good will, it is our hope that if a penitent has committed a crime heinous in nature that they allow justice to take its course so that those hurt by that or whatever crime may be find peace and bring closure to that painful chapter in their lives.
"Be subject for the Lord's sake to every human institution, whether it be to the emperor as supreme, or to governors as sent by him to punish those who do wrong and to praise those who do right. For it is God's will that by doing right you should put to silence the ignorance of foolish men. Live as free men, yet without using your freedom as a pretext for evil; but live as servants of God. Honour all men. Love the brotherhood. Fear God. Honour the emperor." 1 Peter 2:13-17