I personally don't think too many people would admit that they considered the punishment at the time of the crime but it is possible that they do. The reason for the lack of admission is some crimes take intent into account. If you intended to do harm/kill someone, that is one crime. If you intended to break up a fight and killed someone through some incredibly poor choices, that is a different crime. And so on.
On the other hand, there are some people who start a crime and can't carry it out. Perhaps some of them had a little fear or a little conscience at the last second.
The police sometimes cuff people even if they are being cited as opposed to arrested. A small segment of the population fear that this small offense will be front page news and they will run for it or do other crazy things.
Solfe
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'That was tops! Who's not good at math? I was all, "Four!"' - Finn, Adventure Time.