Was sin necessary for knowledge?

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I think sociopaths do have moral knowledge, they just don't care.

As for insanity, I do think that a person who is insane enough may not be culpable for their immoral action, and so is not guilty of sinning.

Sin requires wrongful action AND moral culpability.

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I respectfully ask for a clarification on this point. Since I can assume you're catholic, would you define sin as needing either full knowledge, deliberate consent or the act is objectively and intrinsically immoral as defined in the catechism? These would be Mortal sins and Venial sins. Both are actions and not what I read in the original post. I thought we were attempting to nail down a definition for the noun sin. I believe sin (n.) exists outside of people but is dependent on actions of people as it is a choice against an objective moral authority.

We can use insane people, or puppies or babies if that makes the discussion more emotive, feel free to interchange them. I believe that someone can act intentionally against God, without full knowledge and it be objectively immoral, and it is still a sin.

ie. - sociopath/insane/baby/puppy decides to just randomly slit a stranger's throat. It was deliberate in the moment, but they were delusional at the time (didn't understand societies view for puppies and babies) so no full knowledge, and murder is intrinsically immoral.  Under my definition it would be a sin. I don't believe it would be under the catholic catechism. I'm curious as to the general atheistic and agnostic thought on punishment/culpability.

Just so this is not a derailing, has the consensus to the OP agreed that sin is not necessary for knowledge?