Killing Under Duress

What makes a good serial killer?
Nurture or nature?
No one knows for sure.

He killed dozens, slaughtered entire families. Retirees, college students, executives. None was exempt.
Yet he didn’t think of himself as a serial killer.
After all, all the killings was because someone had told him to.
And no, he was not an assassin. At least assassins got paid.
He didn’t like it. Not one bit.
But what was he supposed to do?
After all, the person who'd taught and ordered him to kill, was the person who'd raised him.