22. In the sacrament of reconciliation, the Christian faithful obtain from the mercy of God pardon for their sins. At the same time, they are reconciled with the Church, which they have wounded by their sins and which works for their conversion by charity, example, and prayer (Lumen Gentium, n. 11).
23. Only those who have the use of reason are capable of committing serious sin. Nevertheless, even young children and persons with mental disabilities often are conscious of committing acts that are sinful to some degree and may experience a sense of guilt and sorrow. As long as the individual is capable of having a sense of contrition for having committed sin, even if he or she cannot describe the sin precisely in words, the person may receive sacramental absolution. Those with profound mental disabilities, who cannot experience even minimal contrition, may be invited to participate in penitential services with the rest of the community to the extent of their ability.
24. Catholics who are deaf should have the opportunity to confess to a priest able to communicate with them in sign language, if sign language is their primary means of communication. They may also confess through an approved sign language interpreter of their choice (Canon 990). The interpreter is strictly bound to respect the seal of confession (Canons 983, sect. 2 and 1388, sect. 2). When no priest with signing skills is available, nor sign language interpreter requested, Catholics who are deaf should be permitted to make their confession in writing. The written materials are to be returned to the penitent or otherwise properly destroyed.
25. In the case of individuals with poor communication skills, sorrow for sin is to be accepted even if this repentance is expressed through some gesture rather than verbally. In posing questions and in the assignment of penances the confessor is to proceed with prudence and discretion, mindful that he is at once judge and healer, minister of justice as well as of mercy (Canons 978, sect. 1; 979; 981).
SOURCE: Guidelines for the Celebration of the Sacraments with Persons with Disabilities (USCCB)