They say every criminal makes at least one mistake which gives them away. It may be subtle and on the face of it, may seem unimportant until you think about it. The following excerpt from one of Ann Eaton's statements has bugged me since first reading it - a perfectly innocent comment about his father's wallet doesn't seem too sinister on the surface. However, how did Jeremy know how much was in the wallet? Is it likely that Neville would broadcast the contents of his wallet? Such things are surely not discussed - but Jeremy knew how much was in the wallet and the other contents - as though he had recently looked inside it.
Did he count it after killing five people, leaving it behind to claim later? And in his haste to find it, did he make a Freudian slip?