Here is a tidbit from the novel ….
[He] was a killer with a conscience …. A thing had to feel right to him. Killing a child, for instance, didn’t feel right. So he would never do it. Ever.
Killing a woman, on the other hand, was a different matter. He would prefer not to kill this woman, but he would do it if it couldn’t be avoided. Unfortunately for her, it didn’t look like it could be.