Eliezer Yudkowsky. Harry Potter and the methods of rationality (№ 401635)

If, in fact, commit the perfect crime, nobody will know about it. How then can you know exactly that there is no perfect crime?
If you look from this angle, it becomes clear that, perhaps, perfect crimes are committed constantly. The coroner announced that the death was from natural causes, the newspaper reported that the store never brought a substantial profit and finally closed down...