Another option would be for the priest to tell the penitent “You know I cannot and will not take any action about this, or tell anyone, because you told me this during your confession. However, if you wish, you may remain after I give you absolution. Your confession will then be over. If you wish to tell me anything after that, I will not be bound by the seal of confession.”
When I was going through confirmation, the priest told me the rules on confession were the same in or out of the booth.
Now the standard is inside the booth.
Is the priest supposed to call the authorities and say, “someone confessed a crime in the booth. It may or may not be a member of my parish?”