The underlying guilt of bringing harm to another undeserving soul was what prevented the vampire from daring to pounce. That changed when the overwhelming hunger had engulfed the American has he roamed the dark streets. He had finally found someone.

You had fell victim on your walk home from work. Jumped by a towering figure and a sharp pain blooming within your neck as teeth sank within your skin.

He found it to be oddly enjoyable, pleasure overriding the guilt.