To Kill A Killer

The main character's ambiguous morality added layers to the story. I'm curious whether this was planned from the start or developed during writing.

The story kept me on the edge of my seat, but at times I wondered if the quick pace sacrificed some character depth. What do others think?

The tension was high, yet there were brief pauses that made me think about the characters' motives. Was this structure something the author consciously crafted?