Complete the short story / flash fiction, that has the following first paragraph:
“I can’t do it,” I thought to myself. This was my son in front of me. My only son. The fact that he brutally murdered his father doesn’t take that away, it only makes this harder. The gun was shaking in my hand as I pointed it at him, but all I could see were the corners of his mouth slowly pulling up in a humourless grin. His hands dropped to his sides as he looked at me. He opened his mouth to speak, but the sound of a gunshot startled me.
Post a link to the story in the comments.