Psychopaths make up 4.5% of the adult population, according to a new meta-analysis

[Skeptic]

@Brainspore

Psychopaths are primarily (exclusively?) motivated by self-interest. In most contemporary settings murdering another human being is far more likely to make a person’s life worse than it is to make their life better, regardless of whether the killer has any actual empathy for their victim.

The problem, though, is that psychopaths can also have a reduced fear of negative consequences and a high regard for their own cleverness and ability to get away with crimes. So the risk benefit ratio that you are positing will keep them in check, isn’t actually calculated the same in their brains as it would be in ours.