Dorothy L. Sayers said this quote

I looked for any footmarks of course, but naturally, with all this rain, there wasn't a sign. Of course, if this were a detective story, there'd have been a convenient shower exactly an hour before the crime and a beautiful set of marks which could only have come there between two and three in the morning, but this being real life in a London November, you might as well expect footprints in Niagara. I searched the roofs right along—and came to the jolly conclusion that any person in any blessed flat in the blessed row might have done it.