The law in many western countries calls for very harsh penalties for possession of child pornography (even without making it, paying for it, or distributing it).
I have speculated that one key element of public support for those penalties is assumptions about the state of mind of the viewers. The average person assumes that the viewers take pleasure from the child's suffering, think it's just fine that the child suffered for their pleasure, and feel no remorse.
I have been conducting an ongoing anonymous survey in the Virtuous Pedophiles online support group on this subject.
As of today, 50% of those who have seen CP at some point have chosen "I feel really bad about getting sexual enjoyment from a child's abuse".
Now, this is not a random sample of pedophiles or CP viewers. The VP support group is primarily composed of those who are against legalizing adult-child sex. So it is a biased sample.
Still, when you hear that someone has been found with CP images, keep in mind the strong possibility that they feel terrible about it -- and felt that way before they were caught, a point after which expressing remorse might involve self-interest. I don't in this post want to list the other options (though the vast majority of the others did not want the child to suffer), because they are ones that tend to give rise to an emotional response. I want to focus attention on the 50% who did not choose those options.
Elsewhere in the law, we assume the best intentions of criminals until worse intentions are proven. First degree murder involves premeditation, and the prosecution has to prove premeditation. If it is unclear, then the suspect can be convicted only of second degree murder. Another case is that often there are more severe penalties if a crime is motivated by the victim's race (or religion or ethnicity) and thus a hate crime as opposed to motivated by more ordinary factors. The prosecution has to prove the motivation involved the victim's race.
In considering proper penalties for CP possession, you (as a citizen whose voice ultimately determines the proper penalties for crimes) should be assuming that the victim felt bad about their viewing. You might feel that more severe penalties would be warranted for those who feel no remorse, but if so it should be up to the prosecution to prove lack of remorse.