We aren't laughing at the casualties. Just the dry, understated comment by the Sherrif, and the stupidity of the reporters. It is called sarcasm. The implication is that they would have shot the perp more times if they would have had more bullets. I think those of us who laughed at the comment pictured ourselves in the same situation and agreed with the sentiments. For what the blankety-blank did, 68 bullets wasn't enough.