Addressing the consequences of neuroscientific findings on the law, the problem of how to consider the psychopath who is under trial is an helpful sanity check of every new proposed theory. On one hand, recent studies show that the psychopaths' brain is often abnormal and that the abnormality is strictly correlated to their misbehavior. But it remains unclear whether the psychopath is really unable to restrain himself from doing harm to others. On the other hand, one could claim, as it actually happens, that the psychopaths are the most evil criminals, just because they can't feel empathy for their victims but they wouldn't pass the «policeman test». In other words, they wouldn't do harm to others if a policeman pointed a gun at them. We'll discuss all the implications on the law in the light of the target article.