The laugh was a thing that he'd not expected. Though once he was aware that it was Erik, he'd stopped thinking about being arrested and other such interruptions to his life. He thought, at most, that there might be a demand for explanations, and a possible rift in their friendship. He was quite sure, however, that Erik would not care about the dead man anymore than he'd cared about Hannibal eating a section of his heart. He also didn't think that Erik would sacrifice his talent in the face of a transgression such as this one.
But the laugh...
Hannibal knew he had never heard the other man laugh. It was foreign enough to see him smile, just a little bit. The sound rang in his ears as he turned and stood fluidly, not bothering to hide the knife in his hand or the blood on his skin.
"I suppose I'm pleased that you find this so amusing." He raised an eyebrow. The man on the floor behind him was not quite dead yet. Hannibal had been in the midst of explaining the value of taking your sheet music home with you, and hadn't wanted an expiration of life before the point was made. There was a light pleading gurgle.