The mark was put by Barker's bloodstained slipper upon the windowsill to suggest how the fugitive got away. They obviously were the two who must have heard the sound of the gun; so they gave the alarm exactly as they would have done, but a good half hour after the event.
巴克用他沾了血跡的拖鞋在窗臺上做了腳印，偽作兇手逃走的痕跡。他們顯然是兩個肯定聽到槍聲的人，所以在他們安排好了以後，才拉鈴報警。不過這已經是案發後整整半個小時了。