Then he *probably* wasn't a psychopath.
Psychopath's and sociopaths are just wired up differently and in extreme cases find it literally impossible to feel empathy at all.
Of course there are grades of psychopath and it's widely believed that 20% + of super successful CEO's and a similar number of politicians are psychopaths, but most don't go on to kill.
By the same token they struggle with genuine feelings of empathy or compassion for anybody who gets in their way.
There is nothing either good or bad, but thinking makes it so.