Never gave this much thought, but from the “Ite ad Thomam” site:
So stealing from a church is actually two sins, theft and sacrilege? Or is it still one – sacrilegious theft?
Two sins. And both have to be confessed. In other words, it’s not enough to say merely “I stole something from a building,” or “I committed sacrilege at the church”; one has to confess having stolen from the church, both theft and sacrilege. And so with other acts that involve multiple species of sin, as when one does one bad thing for the sake of another.
Something to think about…