[armydoc]

The Good Thief made a Perfect Act of Contrition.

Hmm. It was always my understanding that a "perfect act of contrition" substituted for priestly absolution of a mortal sin in circumstances when a priest could not be accessed for the sacrament of Penance; it has nothing to do with unpaid temporal punishments. Are you saying that a "Perfect Act of Contrition" serves as a Plenary Indulgence?

[Salvation]

I might be mistaken there. Checking it out.

[Salvation]

I'll let a priest answer this for you.

The Three Crosses: The Good Thief or the Cross Accepted

[Mad Dawg]

If you want to get all technical ...

Some teach that Baptism removes all the effects of sin, including "the temporal penalty of sin." That's why if you want to become Catholic, if you've been validly baptized you ordinarily have to go to confession before reception, confirmation, etc. But if you have not been baptized, no confession is required.

I would think of "Dismas" as receiving the Baptism of Desire (since the 'desire' for Christ is the point, not the desire for a sacrament of which one might never have heard.

I think it's the wrong emphasis to say a perfect act of contrition (which would be a phenomenon of grace, BTW) "serves as a Plenary Indulgence." It's like saying a football player's being levitated to the end zone, "served in place of a run." It's more like plenary indulgences (and running) are that to which we take recourse because levitation and perfect acts of contrition are not usually available.

This is not authoritative. This is Mad Dawg winging it.