ten o'clock
Then , there being no one about , he made some notes of the chat with Elkin . The man 's candor and his misstatements were equally puzzling . None knew better than the policeman that the vital discrepancy of fully an hour and a half on the Monday night would be difficult to clear up . Tomlin , of course , would have no recollection of events after ten o'clock , but the commercial traveler , who could be traced , might be induced to tell the truth if assured that the police needed the information solely for purposes in connection with their inquiry into the murder . That man must be found . His testimony should have an immense significance . That evening , shortly before seven o'clock , a stalwart , prosperous-looking gentleman in tweeds `` descended '' from the London express at Knoleworth .