Place this clip at the end of a short confession scene, just before the reveal, then follow it with the Law and Order Dun Dun sound for a mock courtroom beat. Put a surprised reaction sound before it so the line lands as the payoff.
About this sound
This 2.8-second clip has Ned Flanders cheerfully announcing that he is a mur-diddely-urder, stretching the word murder through his familiar diddely speech pattern in a bright, upbeat voice. It feels funny and jarring because the friendliest neighbor in Springfield sounds proud of something dark. The line comes from The Simpsons.